Trout leads stacked AL rookie field, Harper facing two-man battle in NL

While the National League is a two-man race between a budding superstar and a budding innings eater, the AL has a deep rookie pool of candidates, and one that could be getting deeper. Seattle's Jesus Montero has hit .302/.357/.476 since the day after I last visited this award three weeks ago, Tampa Bay's Matt Moore has a 3.04 ERA and has struck out 10.6 men per nine innings over his last four starts, three of them quality and Oakland's Yoenis Cespedes has gone 9-for-24 (.375) with three doubles, a triple and a home run in six games since his return from the disabled list on Friday. Those three failed to make my list again this week, but could force their way on three weeks from now.

Note: Rookies are players who, prior to the current season, had fewer than 130 at-bats or 50 innings pitched in the majors or spent fewer than 45 days on the active roster prior to rosters expanding on Sept. 1. The number in parentheses after each player's name reflects his rank on the previous list.

1. Mike Trout, OF, Angels (4)

Season Stats: .329/.385/.538, 5 HR, 22 RBIs, 9 SB (161 PA)

Last Three Weeks: .325/.380/.518, 2 HR, 14 RBIs, 6 SB

Trout wasn't called up until April 28, but the time he missed is already less significant than how well has has played since then. The numbers above speak for themselves, but they leave out his outstanding play in the field, most of it in centerfield, which increases his value considerably.

I said my piece about Trout on Wednesday, so I'll just add this: Trout nearly lost his rookie status last year but Major League Baseball made an exception to keep him eligible for this award. Per my note above, hitters lose their rookie status once they have had 130 at-bats or spent 45 days on the active 25-man roster prior to rosters expanding on September 1. Trout had 123 at-bats last year and spent 38 days on the Angels' active roster prior to September 1. However, according to Major League Baseball's rules, because the span between Trout's July 31 demotion and August 19 recall was less than 20 days, he should have been credited with being on the major league roster the entire time, thus putting him well above 45 days and erasing his rookie status for 2012. Fortunately, the Commissioner's Office realized how absurd that would be and decided to credit Trout only with the actual days he spent in the majors, leaving him eligible for this award. It was the right decision, but one that likely wouldn't have been made for a lesser player.

2. Yu Darvish, RHP, Rangers (1)

Season Stats: 7-3, 3.34 ERA, 1.46 WHIP, 9.8 K/9, 1.92 K/BB, 6.1 IP/GS

Last Four Starts: 2-2, 4.30 ERA, 1.52 WHIP, 8.6 K/9, 1.57 K/BB, 5.8 IP/GS

After an ugly first inning in the major leagues, Darvish dominated for the rest of April, going 4-0 with a 1.13 ERA in five starts. However, since the calendar flipped to May, he has been underwhelming, going 3-3 with a 4.46 ERA and just three quality starts in six turns. Those bases on balls continue to be a problem, as he has walked 5.5 men per nine innings over those last six starts. Still, put all 11 starts together and he leads qualified American League rookies in ERA, wins and strikeouts (73).

3. Wei-Yin Chen, LHP, Orioles (3)

Season Stats: 5-2, 3.49 ERA, 1.30 WHIP, 6.9 K/9, 2.32 K/BB, 6.1 IP/GS

Last Four Starts: 1-2, 5.48 ERA, 1.48 WHIP, 7.4 K/9, 2.38 K/BB, 5.8 IP/GS

On the surface, there's not a lot of difference between the aggregate performances of Chen, the A's Tommy Milone and the Tigers' Drew Smyly, all lefthanded rookies who opened the season in their team's rotations and are sporting ERAs in the mid-threes. Smyly has the best strikeout rate (8.2 K/9) and K/BB ratio (3.24), but has the highest ERA (3.71) and has averaged fewer than 5 2/3 innings per start. Milone, whose ERA is 3.53, has gone the deepest into his games (6.5 IP/GS) and has the lowest WHIP (1.15) but also the lowest strikeout rate (5.2 K/9) and most losses (5).

Chen gets the edge over both of them not necessarily because of any particular variation in his results, but because of context. Milone and Smyly both pitch their home games in pitcher-friendly ballparks. Chen does not. All else being roughly equal, that means Chen has out-pitched the other two, plain and simple.

4. Jarrod Parker, RHP, A's (N/A)

Season Stats: 2-2, 2.40 ERA, 1.21 WHIP, 6.5 K/9, 1.46 K/BB, 6.1 IP/GS (8 GS)

Last Four Starts: 1-1, 2.74 ERA, 1.13 WHIP, 7.0 K/9, 1.50 K/BB, 5.8 IP/GS

Parker didn't join the A's rotation until April 25, so he has made just eight starts compared to the 11 made by fellow rookies Darvish, Chen, Smyly and rotation mate Milone. Still, six of those starts have been quality (and a seventh missed by just one out) tying him with Darvish, Milone and the Diamondbacks' Wade Miley for the major league rookie lead in quality starts (also tying him with Trevor Cahill, the pitcher the Diamondbacks traded him for).

If you take out Parker's one stinker across the bay in San Francisco (2 IP, 6 R), he has posted a sparkling 1.35 ERA in his other seven starts while averaging 6 2/3 innings per outing. There's luck involved there. Parker is a flyball pitcher who has allowed just one home run in 48 2/3 innings. There are also environmental factors, as five of Parker's eight starts have come in his pitching-friendly home park and of this three road games, only one took place in a hitters' park (though he did excel in that one, too, holding the Red Sox to one run over 6 2/3 innings at Fenway Park in his second start of the year, the third of his major league career). Then again, he also faced the top four offenses in the league, holding them to a combined four runs over 28 innings (1.28 ERA) and took a no-hitter into the eighth inning against the Rangers in his last start.

5. Will Middlebrooks, 3B, Red Sox (N/A)

Season Stats: .321/.345/.557, 6 HR, 22 RBIs (110 PA)

Last Three Weeks: .365/.377/.519, 2 HR, 8 RBIs

Middlebrooks was called up on May 2 as an injury replacement for Kevin Youkilis, but has been so productive since that he has survived Youkilis's return and has actually forced the Red Sox to rearrange their defense to keep him in the lineup, bumping three-time Gold Glove-winning first baseman Adrian Gonzalez to rightfield to allow Youkilis to move back to first base. Gonzalez had played rightfield three times in his major league career before Middlebrooks' arrival. He has now played there 10 times in the last 17 games. Youkilis, meanwhile, has suddenly found himself the subject of trade rumors. This is all good news for Boston, as Youkilis is 33 years old, in the final guaranteed year of his contract and has proved increasingly fragile the last few seasons, while Middlebrooks is 23 and was considered the team's second-best prospect coming into the season.

Off the list: Drew Smyly (2), Ryan Cook (5)

1. Wade Miley, LHP, Diamondbacks (1)

Season Stats: 7-2, 2.53 ERA, 1.09 WHIP, 5.5 K/9, 2.56 K/9, 6.6 IP/GS

Last Four Starts: 3-1, 2.54 ERA, 0.95 WHIP, 4.4 K/9, 3.50 K/9, 7.1 IP/GS

2. Bryce Harper, OF, Nationals (N/A)

Season Stats: .285/.369/.515, 5 HR, 14 RBIs (149 PA)

Last Three Weeks: .328/.416/.567, 3 HR, 9 RBIs

What constitutes the best rookie in a given season? Is it the player who contributes the most or the player with the best performance relative to his age and experience? Historically speaking, it's the former, which is why three veterans of Nippon Professional Baseball, including superstar Ichiro Suzuki and then-32-year-old Kazuhiro Sasaki, have won the Rookie of the Year. Given that, the fact that Harper is on pace to have arguably the greatest season by a 19-year-old in the history of the major leagues doesn't outweigh the fact that, to this point, the 25-year-old Miley has been more valuable. Miley has made eight starts and three relief appearances and leads qualified major league rookies in ERA and WHIP and is tied for the rookie lead in wins and quality starts.

3. Zack Cozart, SS, Reds (4)

Season Stats: .245/.292/.420, 6 HR, 14 RBIs

Last Three Weeks: .247/.276/.438, 3 HR, 5 RBIs

The NL field drops off sharply after Miley and Harper, as evidenced by the fact that the third man on this list has a .292 on-base percentage. The average NL shortstop has hit .255/.308/.373 thus far this season, which makes Cozart's line above average for his position. Mix in the fact that he has also been above average in the field and leads all major league rookies in plate appearances and he's the best of the rest.

4. Kirk Nieuwenhuis, OF, Mets (3)

Season Stats: .295/.358/.399, 3 HR, 20 RBIs

Last Three Weeks: .300/.338/.383, 1 HR, 8 RBIs

Thanks to the injury that leftfielder Mike Baxter suffered during Johan Santana's no-hitter, Nieuwenhuis, who had fallen into a platoon with Andres Torres in center, is currently a leftfielder with a .399 slugging percentage. Given that he's not an elite defender, basestealer or on-base machine makes Captain Kirk sub-par for his position. However, Nieuwenhuis has spent the majority of his time this year in center, and the average major league centerfielder has hit .268/.334/.404, making Nieuwenhuis above average there. The total package is somewhere around a league-average player, which given that Nieuwenhuis is one of just five major league rookies to qualify for the batting title at this point in the season (Trout and Harper aren't there yet), is enough to get him on this list.

5. Wilin Rosario, C, Rockies (N/A)

Season Stats: .250/.283/.563, 9 HR, 25 RBIs (120 PA)

Last Three Weeks: .278/.298/.556, 4 HR, 14 RBIs

Rosario opened the season as Ramon Hernandez's backup and made just eight starts in April, but he assumed a larger share of the catching duties in May and ultimately took over as the starter when Hernandez hurt his right hand two weeks ago. As a result, Rosario has had significantly less playing time than Cozart and Nieuwenhuis, which is the primary reason that he trails them on this list.

The 23-year-old Rosario has offensive skills that translate outside of Coors Field (he's hitting .261/.300/.565 on the road, all three better than his home rates), but there's little reason to expect much improvement in his on-base percentage. His career minor league OBP was .316, including a .284 mark in Double-A last year. Rosario has accepted just four unintentional walks thus far this season.

Off the list: Yonder Alonso (2)