Players are graded on a 20-80 scale for future tools -- 20-30 is well below average, 40 is below average, 50 is average, 60 is above average and 70-80 is well above average.
Check out all 30 team Top 20 lists and the Top 100 on Prospect Watch.
1. Lucas Giolito, RHP
Preseason rank: 1
MLB Top 100 rank: 44 (Preseason: 11)
Scouting Grades: Fastball: 80 | Curveball: 65 | Changeup: 55 | Control: 55 | Overall: 65
Giolito was considered to be the top prep pitcher in the 2012 Draft class until a sprained ulnar collateral ligament shut him down in early March. The Nationals made him the No. 16 overall pick anyway, signing him to a well-above slot deal. Giolito made one professional appearance before undergoing Tommy John surgery. He returned to the mound in July of 2013 and showed the same premium stuff that first got the attention of scouts.
Giolito has gotten stronger as he gets further away from his surgery and has as much potential as any pitcher in the Minor Leagues. He showed as much in 2014, making the Futures Game.
Giolito throws his fastball in the mid- to upper-90s, often reaching 100 mph. He throws a hard, 12-to-6 curveball that is almost as good as his fastball. His changeup isn't as well developed as his other two pitches, but it has the potential to be a third above-average Major League offering. He has good command and an advanced feel for pitching.
2. A.J. Cole, RHP
Preaseason rank: 2
MLB Top 100 rank: 69 (Preseason: 63)
Scouting Grades: Fastball: 70 | Curve: 50 | Changeup: 55 | Control: 55 | Overall: 55
The Nationals have acquired Cole twice, first when they drafted him in 2010 and then again in March 2013 in the Michael Morse deal. In between, Cole was part of the package they sent to the A's for Gio Gonzalez. After a disappointing year with the A's, Cole broke out in his return to the Nationals, reaching Double-A Harrisburg and pitching in the 2013 Futures Game.
Cole relies on his fastball, which sits in the mid-90s and reaches 98 mph. He commands the pitch well and isn't afraid to come after hitters with it. Though both his changeup and curveball aren't as advanced as his fastball, both have the potential to be Major League-average offerings.
If Cole can hone his offspeed pitches, he has the potential to be the latest homegrown member of the Nationals rotation.
3. Michael Taylor, OF
Preseason rank: 4
MLB Top 100 rank: 73 (Preaseason: NA)
Scouting Grades: Hit: 40 | Power: 50 | Run: 60 | Arm: 55 | Field: 65 | Overall: 55
Taylor was drafted as a shortstop and then quickly transitioned to the outfield as a professional. His tools and athleticism give him vast potential if he is able to refine his approach at the plate.
Taylor is susceptible to good breaking balls and too often swings at pitches out of the zone. If he can become more consistent at the plate, he has a wealth of raw power to tap into. That, combined with his plus speed, could make him an offensive force.
Taylor is much more advanced defensively. He has a solid arm and his speed allows him to effortlessly cover ground in center field. If his bat continues to come around, Taylor could become a solid everyday Major Leaguer.
4. Erick Fedde, RHP
Preseason rank: None (2014 Draft)
Scouting Grades: Fastball: 60 | Slider: 55 | Changeup: 50 | Control: 55 | Overall: 50
Fedde appeared to be on his way to becoming a top 10 pick in the 2014 Draft until he underwent Tommy John surgery in May. Despite the injury, he didn't fall far on Draft day, as the Nationals grabbed him 18th overall.
When healthy, Fedde usually deals fastballs at 91-93 mph and has reached as high as 95, and the pitch plays up because it has nice life and he can locate it where he wants. His low-80s slider can be inconsistent but should give him a second plus pitch down the road. He also shows flashes of having a useful changeup.
The Nationals have had success helping young pitchers through Tommy John rehab, including 2012 first-rounder Lucas Giolito. They will have to be patient as Fedde recovers, but he should give their system another premium arm.
5. Steven Souza, OF
Preseason rank: 14
Scouting Grades: Hit: 40 | Power: 50 | Run: 50 | Arm: 55 | Field: 50 | Overall: 50
It has been a long, slow climb through the Minor Leagues for Souza since the Nationals picked him in the third round in 2007. After several injuries and a 50-game suspension for testing positive for performance enhancing drugs in 2010, he finally put it all together and made his Major League debut in 2014.
Toolsy and athletic, Souza combines good speed with big raw power. His loose, easy swing allows him to drive the ball to all fields. He uses an up the middle-approach that has helped him cut down on his strikeouts and make better use of his power.
Souza has the tools to be a Major League regular. Since moving to the outfield, he has primarily played right field and profiles best there, but is still athletic enough to handle center field in a pinch.
6. Matt Skole, 1B
Preseason rank: 7
Scouting Grades: Hit: 50 | Power: 60 | Run: 30 | Arm: 50 | Field: 45 | Overall: 45
Skole made waves in 2012, his first full professional season. But his follow-up campaign was brought to an abrupt halt by a collision in the second game of the season that forced him to undergo Tommy John surgery and aprocedure to repair a microfracture in his wrist. He got back on the field in time for the Arizona Fall League, where he played well.
When he's healthy, Skole has never had a problem hitting. He generates impressive bat speed and big power. While there's always going to be some swing-and-miss in his game, he understands the strike zone and knows how to draw a walk.
Originally a third baseman, Skole has moved across the diamond to first base. That puts more pressure on him to hit, but, so far, he's shown that won't be a problem.
7. Brian Goodwin, OF
Preseason rank: 3
Scouting Grades: Hit: 50 | Power: 40 | Run: 60 | Arm: 50 | Field: 55 | Overall: 45
An athletic, toolsy outfielder, Goodwin impressed in his first full professional season, reaching Double-A Harrisburg and finishing the year in the Arizona Fall League. He returned to both leagues in 2013 and had slightly better results.
Goodwin knows how to get on base and, when he's right, uses the whole field to hit. He has worked to simplify his swing, but still has room for improvement, especially against left-handers. Goodwin has some good pop, but his best tool is his plus speed. He uses it on the basepaths well and has the look of a future leadoff hitter. Defensively, he is solid in center field and has a good arm.
If Goodwin can harness all his athleticism, he has the ability to become the Nationals center fielder of the future.
8. Drew Ward, 3B
Preaseason rank: 13
Scouting Grades: Hit: 50 | Power: 55 | Run: 30 | Arm: 55 | Field: 40 | Overall: 45
Originally a member of the 2014 high school class, Ward graduated a year early, making him eligible for the 2013 Draft. Though the move had been in the works for several months, it was difficult for scouts to evaluate him because they hadn't concentrated on him during summer ball. The Nationals picked him in the third round anyway and he made a strong professional debut.
Known mostly for his power before the draft, Ward showed a surprisingly mature hitting approach in his professional debut. Though he was a shortstop in high school, he has already moved to third base. He has a strong arm, but his lack of athleticism limits his range and some scouts think he will ultimately profile best at first base.
Wherever Ward fits defensively, his bat will likely have to carry him.
9. Blake Treinen, RHP
Preseason rank: 17
Scouting Grades: Fastball: 60 | Slider: 45 | Curveball: 45 | Changeup: 50 | Control: 55 | Overall: 45
Treinen came to the Nationals from the A's before the 2013 season as a part of their return in the three-team deal that sent Michael Morse to the Mariners. He'd always flown under the radar, but that changed when he made his Major League debut in 2014.
Treinen throws a power sinker, running it up to 96 mph, as well as a slider and a changeup. He doesn't miss many bats, instead focusing on creating groundball outs with his sinker. He does that with aplomb, aided by his large frame that makes it easy for him to pitch down in the zone.
Treinen began his professional career as a reliever, but has since moved to the rotation. The Nationals believe he has the ability to be a big league starter and he's shown why this season.
10. Austin Voth, RHP
Preseason rank: 16
Scouting Grades: Fastball: 60 | Slider: 50 | Changeup: 45 | Control: 60 | Overall: 45
Voth finished second in the Pac-12 in strikeouts in 2013, behind only eventual No. 1 Draft pick Mark Appel. Voth carried that success over to the professional ranks after getting picked in the sixth round by the Nationals.
He relies on his low-90s fastball and also throws a solid slider and changeup. He repeats his methodical delivery very well, helping him to pound the strike zone with all of his pitches. His plus control allows his whole arsenal to play up and pile up strikeouts.
Voth is built like an innings-eating starter and, as long as he keeps throwing strikes, he could continue on the fast track he put himself on with his stellar professional debut.
11. Jakson Reetz, C
Preseason rank: None (2014 Draft)
Scouting Grades: Hit: 55 | Power: 50 | Run: 40 | Arm: 55 | Field: 50 | Overall: 45
Reetz made a name for himself on last year's summer showcase circuit, earning MVP recognition at the Perfect Game All-America Classic and batting .435 with a team-high five extra-base hits to help the U.S. national team win the 18-and-under World Cup in Taiwan. That performance helped make him the first high school player from Nebraska to be drafted in the top five rounds since 1996.
Scouts are convinced Reetz has the defensive ability to remain a catcher as a professional. He is athletic for a backstop and moves well behind the plate. He has a strong arm, and once he gets accustomed to handling pro-caliber pitchers, he should become a solid receiver.
Reetz can hit, too. He has a quick bat that produces line drives to all fields, and he's strong enough to develop average power. As a bonus, he runs better than most catchers.
12. Pedro Severino, C
Preseason rank: 8
Scouting Grades: Hit: 40 | Power: 30 | Run: 30 | Arm: 65 | Field: 60 | Overall: 45
A native of the Dominican Republic, Severino made his full-season debut in 2013 at Class A Hagerstown. He immediately made an impact, making the South Atlantic League All-Star team and throwing out 40 percent of would-be base stealers.
Severino's plus arm and athleticism behind the plate leave no doubt he has the skills necessary to stick at catcher. He already shows an aptitude for pitch framing and is making progress as a game-caller.
Though Severino's bat is well behind his glove at this point, he has an easy swing that should enable him to hit for average as he gets more experience. He remains a long way off, but his defense will allow the Nationals to be patient as his bat develops.
13. Jefry Rodriguez, RHP
Preseason rank: 9
Scouting Grades: Fastball: 65 | Curveball: 55 | Changeup: 45 | Control: 45 | Overall: 45
Rodriguez was an infielder before signing with the Nationals and moved to the mound as a professional. He made his American debut in 2013, standing out on the Nationals Gulf Coast League team that went 49-9.
Rodriguez has a plus fastball that tops out at 98 mph and his power curveball has plus potential as well. He also throws a changeup, which is still in its nascent stages of development. He has proven to be adept at generating groundballs and showed impressive control for someone so new to pitching.
Thanks to his athleticism and projectability, the Nationals believe Rodriguez still has plenty of room to improve as he gets more experience on the mound.
14. Sammy Solis, LHP
Preseason rank: 5
Scouting Grades: Fastball: 60 | Curveball: 50 | Changeup: 55 | Control: 50 | Overall: 45
Solis has struggled with injuries throughout his career and missed all of 2012 after undergoing Tommy John surgery. He looked as good as ever when he got back on the mound in 2013, but was once again beset by injuries in 2014.
Solis isn't throwing quite as hard as he did before his surgery when his fastball peaked at 97 mph, instead settling comfortably in the low-90s. His changeup is slightly better than his curveball, but both are at least Major League average offerings. He commands all of his pitches well and earns praise for his confident demeanor on the mound.
If he can just stay healthy, Solis has all the tools to get to Washington as a starter. A move to the bullpen is not out of the question, however.
15. Drew Vettleson, OF
Preseason rank: 11
Scouting Grades: Hit: 50 | Power: 50 | Run: 40 | Arm: 60 | Field: 50 | Overall: 45
Vettleson made headlines in high school for being a switch-pitcher. But Major League teams were more interested in his bat and the Rays made him a full-time outfielder after drafting him in 2010. They eventually traded him to the Nationals in February 2014 in exchange for Nathan Karns.
Vettleson has a good feel for hitting, using his short, quick swing to drive the ball to all fields. He has the swing and strength to hit for power, but it hasn't always shown up in games for him.
Vettleson is a solid outfielder with a plus arm, but he'll need to tap into his raw power better to fit the right field profile.
16. Jake Johansen, RHP
Preseason rank: 12
Scouting Grades: Fastball: 65 | Slider: 45 | Curveball: 40 | Changeup: 40 | Control: 45 | Overall: 45
Signing Rafael Soriano cost the Nationals their first round pick in 2013, making Johansen their top selection. He is built like a prototypical Texas right-hander and has the power arm to match.
Johansen throws his fastball in the mid-90s with heavy sinking action. His best secondary pitch is his slider, but it needs more development to become a true weapon. Though his command improved after he signed, he remains more of a thrower than a pitcher.
Johansen has a lot of upside, but many scouts feel he is destined to move to the bullpen. His fastball is good enough to give him a chance to close if he does change roles.
17. Felipe Rivero, LHP
Preseason rank: 18
Scouting Grades: Fastball: 60 | Curveball: 45 | Changeup: 55 | Control: 45 | Overall: 45
Rivero garnered a spot on the World roster for the 2012 Futures Game and impresses scouts with his combination of stuff and feel for pitching. It is now up to the Nationals -- who acquired him as a part of their return for Nathan Karns in February 2014 -- to hone those tools into Major League talent.
Rivero throws his fastball in the low-90s with tailing action. His curveball flashes good potential, though his changeup is the more consistent of his two secondary offerings.
Rivero throws a lot of strikes, but he doesn't always repeat his delivery well and gets hit when he leaves the ball up in the zone. There's is a lot of potential in his lithe frame if he can harness it.
18. Tony Renda, 2B
Preseason rank: 20
Scouting Grades: Hit: 50 | Power: 30 | Run: 50 | Arm: 45 | Field: 50 | Overall: 45
Renda's slight frame makes it easy to overlook him, but he has a history of outperforming expectations. The former Pac-10 Player of the Year played solidly in 2013, his first full professional season.
Renda is an offensive-minded second baseman. His quiet swing helps him make consistent hard contact to all fields. He isn't a speedster and has below-average power. He is a solid defender, capable of making the routine plays well.
Renda isn't flashy in any phase of the game, but he gets praise for his makeup and work ethic, which helps his tools play up. As he continues to climb through the Minor Leagues, he'll have to keep proving himself, something he's been adept at doing so far.
19. Nick Pivetta, RHP
Preseason rank: None
Scouting Grades: Fastball: 60 | Curveball: 50 | Changeup: 45 | Control: 45 | Overall: 45
Pivetta played for the Canadian Junior National team while in high school and headed to New Mexico Junior College after going undrafted in 2011. There, he impressed scouts with his big arm and ideal pitcher's frame.
Pivetta's fastball touched 97 mph when he worked out of the bullpen in college, though it typically sits in the low 90s when he starts. There is some projectability left in his 6-foot-5, 220-pound frame, and he could end up pitching with a tick more velocity. He also has the makings of solid curveball and is working to improve his changeup.
Pivetta remains somewhat raw, but the Nationals like the upside and feel he can become a Major League starter in time.
20. Wilmer Difo, SS/2B
Preseason rank: None
Scouting Grades: Hit: 50 | Power: 40 | Run: 70 | Arm: 55 | Field: 45 | Overall: 45
A late bloomer, Difo struggled in the low minors before breaking out as a 22-year old in the South Atlantic League. His performance has been one of the biggest surprises of the year and he ranked among the Minor League leaders in hits and stolen bases in the first half.
Difo's biggest strides this season have been in the mental aspect of the game. He previously struggled to cope with the failures inherent to baseball, but has become better equipped to handle adversity.
With a better approach to the game, Difo's tools have had a chance to shine through. He's a plus runner and fits well at the top of the lineup. He can play anywhere in the infield and has split his time between shortstop and second base this season. He earns praise for his athleticism and work ethic, which will help him improve as a defender no matter what position he eventually settles into.