Here's a midseason status report:
Preseason and post-spring front-runners
Aaron Hicks, OF, Twins: Hicks has shown flashes of brilliance, with eight home runs at the break and a handful of amazing defensive plays in center field. But he's still under the Mendoza Line and has a .630 OPS. He's going to have to show a lot more in the second half.
Jurickson Profar, IF, Rangers: The main question with Profar, who's only 20, was where he would play. He found some everyday time when Ian Kinsler was hurt, and Texas has kept him up with the big club as a super-utility player, but his bat hasn't caught fire yet.
Bruce Rondon, RHP, Tigers: The Tigers might have been hoping Rondon would win their closer role coming out of Spring Training, but he couldn't find the plate consistently with his serious gas and was optioned to Triple-A Toledo. An April promotion didn't last long, but the club is hoping the 22-year-old will do better now after his second callup in late June.
Trevor Bauer, RHP, Indians: So far the right-hander is more known for his pregame warmup routine and rap songs than results on a Major League mound. Bauer's only 22 and had some bright spots last year in a brief stint with Arizona, but he did not make Cleveland's Opening Day rotation and has struggled with command in his callups this year, with 16 walks in 17 innings in The Show in 2013.
Jackie Bradley Jr., OF, Red Sox: Bradley wasn't being talked about for the AL Rookie of the Year Award until he made Boston's Opening Day roster with a big spring. But things haven't panned out for him just yet. He's been up and down from Triple-A and has struggled offensively in limited at-bats.
Wil Myers, OF, Rays: It seemed to be more a matter of "when" than "if" with Myers after the much-ballyhooed multiplayer trade from Kansas City that landed James Shields for the Royals. Myers didn't make it to the bigs until June 18, but he's shown he belongs, with a .288 average, three homers and 15 RBIs in his first 104 at-bats.
Jose Iglesias, IF, Red Sox: Everyone always loved the glove but didn't know if the bat would work in the big leagues. So far, Iglesias has taken advantage of his opportunity and hit better than anyone could have imagined, with a .367/.417/.471 line after 180 at-bats, while flashing Gold Glove-quality leather. He's the current favorite for the AL Rookie of the Year Award as a result.
Also in the mix: David Lough, OF, Royals; Oswaldo Arcia, OF, Twins; Dan Straily, RHP, A's; Nick Franklin, 2B, Mariners; Brad Miller, SS, Mariners; Mike Zunino, C, Mariners.
Preseason and post-spring front-runners
Jedd Gyorko, IF, Padres: Gyorko was expected to hit, and he has. It took a bit of acclimation, and once he really got rolling, he suffered a groin injury that cost him over a month of action. Still, he's got eight homers and 25 RBIs and a line of .272/.330/.440, so things could heat up quickly in the second half and make him a major contender for the NL Rookie of the Year Award.
Hyun-Jin Ryu, LHP, Dodgers: Ryu is 26 years old and was a polished product coming out of the Korean league when the Dodgers signed him for big bucks. That's not the typical rookie profile, and no one knew how his stuff would play in the big leagues, but it's playing more than fine. Ryu is 7-3 with a 3.09 ERA at the break and is on pace to break 200 innings.
Adam Eaton, OF, D-backs: Eaton was a hyped prospect heading into this season after a brief callup last year. And then he hurt his left elbow and didn't play a Major League inning in 2013 until July 9. We'll see what he can do in the second half.
Shelby Miller, RHP, Cardinals: Miller looked fantastic in a six-game stint at the end of 2012, and he looked fantastic enough in Spring Training to earn the No. 5 starter's job for St. Louis. He's also looked fantastic for much of 2013, with a 9-6 record, a 2.92 ERA and 112 strikeouts in 104 2/3 innings that have him among the favorites for the NL award.
Tyler Skaggs, LHP, D-backs: Skaggs has been considered a top prospect since arriving from the Angels in the Dan Haren trade in 2010. At 21 years old, there's plenty of time for him to come into his own. He has a 4.03 in five big league starts this season but hasn't yet locked down a permanent spot in the D-backs' rotation.
Trevor Rosenthal, RHP, Cardinals: If the 100-mph fastball wasn't enough of a reason for pundits to get excited about Rosenthal, his stellar postseason numbers in 2012 (15 strikeouts in 8 2/3 scoreless innings) and stats so far this year (2.20 ERA, 68 strikeouts in 45 innings) are proving his case as a worthy contender. Then again, it's tough for non-closing relievers to win the Rookie of the Year Award.
Yasiel Puig, OF, Dodgers: Not much more can possibly be said about what this man has done since arriving on the scene in early June. He has gone from Cuban defector to Spring Training sensation to Double-A unfinished product to big league phenom in meteoric fashion. As of the break, he's the NL Rookie of the Year Award favorite, but it's probably best to take his career day by day or at-bat to at-bat.
Also in the mix: Jose Fernandez, RHP, Marlins; Matt Adams, IF, Cardinals; Jim Henderson, RHP, Brewers; Julio Teheran, RHP, Braves; Evan Gattis, C/OF, Braves; Marcell Ozuna, OF, Marlins; Nolan Arenado, 3B, Rockies; Didi Gregorius, SS, D-backs; Zack Wheeler, RHP, Mets; Tony Cingrani, LHP, Reds.