Signed for $85,000 out of the Dominican Republic in 2011, the 22-year-old Diaz has a 93-96 mph fastball with late life and the chance to offer a solid three-pitch mix with a developing slider and changeup. He missed most of 2015 with an avulsion fracture in his pitching elbow, then came back to go 1-8, 3.71 ERA with a 91/29 K/BB ratio in 94 2/3 innings at Class A Wisconsin this season.
• Complete Rule 5 Draft results
Though Diaz projects as a starter, he likely will work in relief if he sticks with the Padres in 2017. He has thrown just 236 innings in five seasons as a pro and has not pitched above Class A.
To keep Diaz, San Diego must keep him on its active big league roster during the entire 2016 season. Players selected in the Major League phase of the Rule 5 Draft can't be sent to the Minor Leagues without first clearing waivers and then getting offered back to their original organization for half of their $100,000 Draft price. Injured Rule 5 players may be placed on the disabled list, but they face the same restrictions governing Minor League assignments in subsequent years until they total 90 days on the active roster.
Here are scouting reports on the other 17 players taken in the Major League phase of the Rule 5 Draft:
Luis Torrens, C, Padres No. 23 prospect (from Yankees via Reds)
Signed for $1.3 million out of Venezuela in 2012, Torrens is an athletic defender who also shows some promise at the plate. He sat out 2015 following surgery to repair a torn labrum in his throwing shoulder, then returned and hit .230/.348/.317 in 40 games at Class A Charleston this summer.
Allen Cordoba, SS, Padres No. 21 prospect (from Cardinals)
Cordoba has yet to play above Rookie ball, but he did win the Gulf Coast League MVP award in 2015 and the Appalachian League batting title in 2016 while hitting .362/.427/.495. A gifted hitter who controls the strike zone and has solid speed and defensive skills at a premium position, he's the most talented player taken in this year's Rule 5 Draft -- but also one of the least equipped to survive in the Majors at this point of his career.
Kevin Gadea, RHP, Rays (from Mariners)
The Nicaraguan-born Gadea is a projectable 6-foot-5 right-hander with a low-90s fastball. He recorded a 2.36 ERA with 95 strikeouts in 68 2/3 innings between Rookie ball and Class A.
Armando Rivero, RHP, Braves (from Cubs)
A Cuban defector who signed for $3.1 million in 2013, Rivero has spent most of the last three seasons in Triple-A and led Pacific Coast League relievers in strikeouts (105), strikeout rate (14.0 per nine innings) and opponent average (.169). He works with a mid-90s fastball and a hard slider.
Tyler Jones, RHP, Diamondbacks (from Yankees)
Jones mirrors Rivero as a right-handed reliever with a fastball that climbs into the mid-90s and a hard slider. He had a 2.17 ERA and a 67/11 K/BB ratio in 45 2/3 Double-A innings.
Caleb Smith, LHP, Cubs (from Yankees via Brewers)
Smith has a low-90s fastball and is actually more effective against right-handers because his best secondary offering is his changeup. He saw action as both a starter and reliever in Double-A, posting a 3.96 ERA and 70/20 K/BB ratio in 63 2/3 innings.
Justin Haley, RHP, Twins (from Red Sox via Angels)
Coming off a 13-10 season with a 3.01 ERA and 126/45 K/BB ratio in 146 2/3 innings in the upper Minors, Haley has a better chance to stay in the Majors than most Rule 5 picks. He's a four-pitch starter with a low-90s fastball and an effective slider.
Dylan Covey, RHP, White Sox No. 28 prospect (from Athletics)
The 14th overall pick in the 2010 Draft -- he didn't sign after a post-Draft physical revealed diabetes -- Covey is another four-pitch righty. His best offerings are a low-90s sinker and a changeup with splitter action. An oblique strain limited him to six Double-A starts this year.
Tyler Webb, LHP, Pirates (from Yankees)
A classic southpaw specialist, Webb shuts down lefties with his low-90s fastball and his slider. He's a good bet to stick in the big leagues after posting a 3.59 ERA and 82 strikeouts in 72 2/3 Triple-A innings.
Daniel Stumpf, LHP, Tigers (from Royals)
The Phillies took Stumpf in last year's Rule 5 Draft, but returned him to the Royals after he gave up six runs in five innings and drew an 80-game suspension for a positive steroid test. Like Webb, he's tough on lefties with a low-90s heater and his slider.
Aneury Tavarez, OF, Orioles No. 30 prospect (from Red Sox)
Tavarez hit .335/.379/.506 in Double-A this year, missing out on the Eastern League batting title by .0001. His best tool is his plus speed, though he's not a prolific basestealer and fits better defensively on the outfield corners.
Glenn Sparkman, RHP, Blue Jays (from Royals)
Sparkman led the Minors with a 1.56 ERA in 2014, but he injured his elbow and had Tommy John surgery in 2015 and recorded a 5.22 ERA at four levels in 2016. He has fringy stuff but gets by thanks to his feel for pitching and the life on his fastball and changeup.
Josh Rutledge, INF, Red Sox (from Rockies)
A veteran of five big league seasons, Rutledge spent 2015 and 2016 with Boston before electing to become a free agent and signing with Colorado (his original organization) after the Red Sox outrighted him in November. He hit .265/.345/.388 in 49 big league at-bats before having season-ending left knee surgery in August.
Hoby Milner, LHP, Indians (from Phillies)
The son of Brian Milner, who went straight from high school to the Majors as a seventh-round bonus baby with the Blue Jays in 1978, Hoby had a 2.49 ERA and a 76/15 K/BB ratio in 65 innings between Double-A and Triple-A. He stands out more for the life and deception he creates from his low arm slot rather than his actual stuff.
Mike Hauschild, RHP, Rangers (from Astros)
Hauschild has spent most of the last two years in Triple-A, posting a 3.22 ERA and 119/40 K/BB ratio in 139 2/3 innings in 2016. He has average stuff across the board, starting with a low-90s fastball.
Stuart Turner, C, Reds (from Twins)
A third-round pick in 2013, Turner is a defensive specialist who may be able to carve out a backup role in the Majors. He batted .239/.322/.363 in Double-A while throwing out a Southern League-best 40 percent of basestealers.
Anthony Santander, OF, Orioles No. 15 prospect (from Indians)
Santander hit .290/.368/.494 with 20 homers in Class A Advanced this year, though he had right shoulder surgery after the season. He's a switch-hitter with power from both sides of the plate, and Baltimore may be able to stash him on the disabled list for a while.