Updated Top 25 MLB prospects

Bryce Harper seems a lock to remain near the top of the prospects rankings. But how long will he qualify? Getty Images

Because I don't have enough going on right now, I thought this might be a good time to revisit my offseason pro prospects ranking and make some changes to the Top 25 based on graduations and early reports. The update is based on conversations with scouts and front-office executives about these players, but the basis is the more extensive work and larger samples that went into the offseason Top 100. If I moved a player substantially from that list, it's because something tangible has changed.

Any player currently in the majors is ineligible for the list since, should he stay in the majors the rest of the year, he'll lose his rookie status for 2012 and will no longer qualify for the rankings by January.

1. Mike Trout, CF, L.A. Angels: He's still just 19 and hitting .294/.403/.506 in Double-A, and getting better as the season goes on, with a .333/.462/.495 line in May and more walks than strikeouts for the month. He offers plus defense in center, plus speed, plus bat and future above-average power, and could help the Angels later this year if they can find their way out of the Sea of Disappointing Outfielders. Previous position: No. 1

2. Bryce Harper, RF, Washington: Hitting .326/.412/.584 as an 18-year-old (14 months younger than Trout) in low-A, although I can't imagine he'll see the end of June there. Harper barely played center earlier in the year but started there five times in the past nine games, a shift that would drastically increase his value. The trouble he had with off-speed stuff in Arizona hasn't been an issue in the Sally League and he's also showing patience he didn't have when playing just twice a week in Fall League. He won't get to the majors this year, but should make his debut in the second half of 2012. Previous position: No. 2

3. Jesus Montero, C/DH, N.Y. Yankees: A weird April, when he hit for average with no walks -- literally, zero walks -- and little power has been followed by a May when he drew a few walks but hasn't hit either. (He's in the midst of one of those meaningless hitting streaks that gets overreported -- "Montero has hit safely in 10 straight games!" -- since he's a whopping 11-for-41 in that span with 16 punchouts.) I'm holding on this one, because I think he'll hit and no one is reporting anything significantly wrong with him except over-eagerness at the plate; I imagine there's some frustration that the Yankees are employing a guy hitting .174/.292/.348 in a spot Montero could fill. Previous position: No. 4

4. Shelby Miller, RHP, St. Louis: Tore up the Florida State League (81 K's in 53 innings at age 20) and earned a promotion this past weekend to Springfield ... which I'm sure will rename itself Shelbyville shortly. Previous position: No. 9

5. Julio Teheran, RHP, Atlanta: He's not ready for the big leagues, but if you saw either start you could see the potential. I can't imagine this up-and-down nonsense is going to do him any good, especially since he has multiple areas for development (fastball command and breaking ball, for starters) before he's really ready. Previous position: No. 6

6. Matt Moore, LHP, Tampa Bay: Multiple reports of improved command beyond just the reduced walk rate. The Rays don't operate this way, but in a lot of organizations he'd be on speed-dial for the next opening in the big league rotation. Previous position: No. 16

7. Martin Perez, LHP, Texas: He's been handled very gently, crossing 100 pitches only once, and his command is still a half-grade below where you'd want it to be. The up-and-down issue with his stuff from last year is gone, and while I don't love guys who repeat levels, he's got a 2.01 ERA in a league where he had a 5.96 ERA last year, missing a few more bats and getting more weak contact. Previous position: No. 18

8. Manny Banuelos, LHP, N.Y. Yankees: Not a great start to the year, although the stuff is largely intact (if not quite as electric as it was in the AFL last year) and he's among the youngest players in the Eastern League. Command was never an issue in the past; this could be a small-sample fluke, it could be that his command was never as good as it seemed, or there could be something more serious wrong. But every source save one said he was still an elite prospect in their views, worthy of a top 10 spot. Previous position: No. 12

9. Desmond Jennings, CF, Tampa Bay: One source noted he seemed "bored" in Triple-A. (Jennings, that is, not the source.) We know he can hit, we know he can play defense and so far he's stayed healthy. Weird but meaningless stat: he has a reverse platoon split, hitting just .242/.319/.452 against left-handed pitchers. Previous position: No. 20

10. Manny Machado, SS, Baltimore: The first major jump here as Machado, currently out with a knee injury, looked better than expected at shortstop and far more comfortable at the plate than expected, adjusting to better off-speed stuff and taking great at-bats in low-A. He won't turn 19 until July, and is just three months older than Harper. Previous position: No. 26

11. Brett Lawrie, 3B, Toronto: Mashing in Triple-A, although part of that is due to where he plays (Vegas) and the fact the PCL has a lot of hitters' parks in its western half. But he can really hit and the raw power is starting to show up in games. There's at least a chance he stays at third base, although I doubt it, but he has the arm and athleticism to play a good right field, and in general has made positive changes that have put old makeup concerns about him (which were reflected even in the January ranking) to rest. Previous position: No. 37

12. Dustin Ackley, 2B, Seattle: He'll hit and gets increasing raves for that tool, but no one is buying him as a second baseman anymore, and I believe he'll end up in left field where his value takes a hit. But he's so good at the plate that he'll still be an above-average player, just not the franchise guy I expected when he was at second or in center. Previous position: No. 7

13. Jacob Turner, RHP, Detroit: Just turned 20 last week, but is showing power stuff and unexpected control in Double-A. Needs to tighten command of his off-speed stuff, but this looks like a No. 1 starter in the making as long as he stays healthy. Previous position: No. 22

14. Wil Myers, RF, Kansas City: Out since May 10 with a knee infection, and off to a slow start before that after an aggressive move up to Double-A as he'll play the whole year at age 20. Still a fan of the bat, but his value took a hit with the move to the outfield (why not third base?) and he may still be ranked a little too high. Previous position: No. 8

15. Casey Kelly, RHP, San Diego: Main issue has been repeating the curveball, but when it's on it's an above-average pitch. San Antonio's a good place to pitch, the rest of the Texas League is full of hitters' parks, and as you'd expect he's got a fat home/road split. Scouts, execs and I, who like him, all buy into the athleticism and arm strength, but he's definitely not as close as I thought two years ago. Previous position: No. 19

16. Jarrod Parker, RHP, Arizona: Still coming back from 2009 Tommy John surgery. Stuff is there, command isn't, although six walks in his past 20 innings (versus 17 in his first 23 innings) is a positive sign. Just be patient. Previous position: No. 25

17. Anthony Rizzo, 1B, San Diego: Some of this is the ballpark -- he's hitting .410/.500/.795 in Tucson -- but some is just him growing into more power. He's still just 21 ('til August), already in Triple-A, and flashing above-average defense at first. He's blocked only by the audacity of Hawpe. Previous position: No. 38

18. Jarred Cosart, RHP, Philadelphia: Back to 93-98 mph again with a knockout upper-70s curveball. He had a brief stretch where he looked mortal as the Phillies had him experimenting with a spike curveball, but once he junked that he was back to his old dominant self. Previous position: No. 34

19. Jameson Taillon, RHP, Pittsburgh. Big velocity, not missing a ton of bats, but also being used gingerly -- he's faced 20 batters in just one of his seven starts, and it's not due to poor performance. Could be more of a 2012 breakout when he's in high-A and given more latitude. Previous position: No. 30

20. Lonnie Chisenhall, 3B, Cleveland: Started a little slowly, as he is wont to do, but a swing this good won't stay quiet for long, and he'd be a major improvement over Jack Hannahan (now slugging .205 in May) when there's a righty on the mound. Chisenhall's struggles against southpaws continue, with a .197/.286/.344 line, which presents a developmental challenge if he reaches the big leagues, although he's at least making contact against them. Previous position: No. 39

21. Jonathan Singleton, LF, Philadelphia: Two things to note about Singleton. One is that the Phillies also made some tweaks with him, getting him to hit off his toes more and in the process slicing more than 150 points off his OPS, but he undid the adjustment about 10 days ago and is hitting again. The other is that his season line hides a big platoon split: he's just 6-for-43 against lefties but hitting .313/.400/.438 against right-handers. He's got great balance, a very good feel for the strike zone, and forces the pitcher to come to him rather than expanding the zone. He's only 19 and didn't play a full year last year, so we need more reps versus left-handed pitchers before the platoon split is a real concern. Previous position: No. 27

22. Miguel Sano, 3B/OF, Minnesota: In extended spring training, so no change here. He's only 18 and might not quite be ready for a full-season league. Previous position: No. 29

23. Devin Mesoraco, C, Cincinnati: Still 22 for a few more weeks, hitting .295/.380/.481, and catching, although in a small sample his success rate in nailing basestealers has dropped, though arm strength has never been a question for him. And by the way, fellow Reds catching prospect Yasmani Grandal is hitting .284/.411/.503 in his full-season debut in Bakersfield, although I'd like to see him perform in Double-A before I jump him up the rankings. Previous position: No. 31

24. Jean Segura, SS, L.A. Angels: Got off to a great start but hamstring problems have sidelined him three times, and he hasn't hit since the injury started. I can't downgrade a player on an injury that isn't, or shouldn't be, a long-term problem. Previous position: No. 35

25. Carlos Martinez, RHP, St. Louis: Multiple sources have him hitting 100 mph as a starter this year, and he's getting Pedro comps. The Cardinals are really taking it easy with him, giving him at least six days of rest between starts, so that velocity might not hold, but we're talking three plus pitches with good feel right now. Previous position: No. 52

Players who fell: Tyler Matzek, LHP, Colorado (velocity down, command gone; I'm assuming he's hurt); Mike Moustakas, 3B, Kansas City (scouts questioning his glove and even his hit tool); Mike Montgomery, LHP, Kansas City (struggling with command); Kyle Gibson, RHP, Minnesota (performing but stuff has been ordinary enough to lower the ceiling); Aaron Hicks, OF, Minnesota (tools are intact, but power still isn't showing up in games and scouts are questioning the left-handed swing).

A few more I'm watching for the next update: Oswaldo Arcia, OF, Minnesota; Jonathan Schoop, SS, Baltimore; Zack Cox, 3B, St. Louis; Matt Harvey, RHP, N.Y. Mets; Arodys Vizcaino, RHP, Atlanta; Anthony Ranaudo, RHP, Boston; Jurickson Profar, SS, Texas.