Top five prospects likely to follow Harper and Trout to the Show

With the arrival of outfielders Bryce Harper and Mike Trout this week, five of Baseball America's six pre-season prospects are in the majors (only Atlanta's Julio Teheran, who debuted last year but is currently pitching at Triple-A, is still in the minors).

So who's next? The answer may not be anyone right away as teams are often wary of calling up top prospects early enough that they'll be eligible for Super Two arbitration, but that risk will disappear by the end of the month, at which point several more of the game's top young talents could arrive in the Show. Using the combined rankings from the top-100 prospect lists by Baseball America and Baseball Prospectus's Kevin Goldstein, here are the top five prospects likely to make their major league debuts this season.

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1. Trevor Bauer, RHP, Diamondbacks (No. 9 BA, No. 11 KG)

The third overall pick in last year's draft, Bauer was in Double-A before the year was over, striking out 26 men in 16 2/3 innings at that level just months removed from UCLA. This year, the 21-year-old wasn't cut from major league camp until March 23 and has since gone 5-0 with a 1.26 ERA and 37 strikeouts in 28 2/3 innings back at Double-A. With Daniel Hudson on the disabled list due to shoulder problems, Josh Collmenter recently demoted to the bullpen and the defending NL West champion Diamondbacks scuffling along near .500, it would seem only a matter of time before Arizona turns to Bauer, who some expected to be called up last September.

2. Travis d'Arnaud, C, Blue Jays (No. 17 BA, No. 16 KG)

Acquired from the Phillies in the Roy Halladay trade in Dec. 2009, d'Arnaud had a break-out year as a 22-year-old in Double-A last season, hitting .311/.371/.542. He got off to a slow start at Triple-A this year, but has hit .390/.435/.610 in his last 10 games. Meanwhile, J.P. Arencibia, the Blue Jays' sophomore backstop, has hit just .171/.213/.257 and now sports a .210 average and .270 on-base percentage in 593 career major league plate appearances. Backup Jeff Mathis has swung the bat well in his five starts, but he's a career .196/.259/.307 hitter in 1,378 career major league plate appearances. There will come a point this season when Toronto won't be able to justify keeping d'Arnaud on the farm any longer.

3. Brett Jackson, CF, Cubs (No. 32 BA, No. 44 KG)

The 31st overall pick in the 2009 draft, Jackson hit .297/.388/.551 after a mid-season promotion to Triple-A last year only to be blocked by the David DeJesus signing this winter. Marlon Byrd's slow start and subsequent trade to the Red Sox opened centerfield back up for the Cubs' top prospect, but now it's on Jackson to earn the promotion. The 23-year-old's .236/.343/.416 line and 28 strikeouts in 22 games thus far this season aren't forcing the Cubs' hand. However, Jackson's teammate Anthony Rizzo (No. 47 BA, No. 75 KG), who already has 128 major league plate appearances under his belt, just might. The 22-year-old first baseman has hit .384/.430/.663 with seven home runs thus far for Triple-A Iowa. The only problem is that his major league counterpart, Bryan LaHair, has been even better, hitting .390/.471/.780 with five homers of his own.

4. Matt Harvey, RHP, Mets (No. 54 BA, No. 25 KG)

Mike Pelfrey's Tommy John surgery has swung the door wide open for this 23-year-old righty from Connecticut via the University of North Carolina. The seventh overall pick in the 2010 draft, Harvey split his first professional season between High-A and Double-A last year, going 13-5 with a 3.32 ERA and 10.3 strikeouts per nine innings. This year, he got off to a slightly rocky start in Triple-A, but has won his last two starts while posting a combined line of 13 IP, 8 H, 3 R, 1 HR, 3 BB, 15 K. The hope in Queens is that Harvey, Jonathon Niese and Zack Wheeler (the former first round pick acquired from the Giants for Carlos Beltran at last year's deadline and currently sporting a 1.75 ERA in Double-A) will head up the Mets' rotation for years to come. With Niese already holding down a spot on the staff, two of those pieces could be in place before the month is out.

5. Yasmani Grandal, C, Padres (No. 53 BA, No. 38 KG)

The top prospect acquired in the Mat Latos trade this offseason, Grandal hit .301/.360/.474 in Double-A last year in just his first full professional season before finishing the year with a 6-for-12 performance at Triple-A. This year, the 23-year-old Cuban has spent more time on the disabled list with a hamstring injury than in the lineup, but he has gone 3-for-10 with two home runs and two walks since returning and is 9-for-22 (.409) on the season while the Padres' catchers, Nick Hundley and John Baker, have combined to hit .205/.292/.337. In part because of his DL stay, Grandal could take a bit longer than the four men above him to force his way into the majors. Still, despite his new three-year extension, Hundley should be looking over his shoulder.