Ten biggest-impact minor league callups for the second half (cont.)

6. Chris Heisey, OF, Reds

Cincinnati has a surprising lack of offense given its ballpark, and could use a right-handed-hitting outfielder to replace Willy Taveras (.590 OPS). It would help if that player could play center field, and Heisey fits that bill. A former 17th-round pick out of Division III Messiah (Pa.), Heisey emerged as a legitimate prospect last year, then was the Southern League's batting leader (.347) before earning a promotion to Triple-A, where he was off to a 10-for-32 start. Scouts grade Heisey as average or above in all five tools, and he has the power, speed and defense to give the Reds a significant upgrade over Taveras for the short- and long-term.

7. Justin Smoak, 1B, Rangers

Texas just sent down Chris Davis due to his .202 average and 114 strikeouts in 258 at-bats. As polished a hitter as Smoak -- the 11th overall pick in 2008 -- is, he can't match Davis' explosive power. But Wieters' former high school teammate does have plenty of power of his own, from both sides of the plate, and is a better hitter, with a more patient approach and better defensive skills at first. Smoak is coming off an oblique strain and has just joined Feliz at Oklahoma City. He'll need to prove he can handle Triple-A pitching, but if he does he could force his way into the Rangers' lineup.

8. John Bowker, 1B/OF, Giants

San Francisco is the current wild-card leader in the National League, but the Giants desperately need more power. Bowker, who hit 10 home runs in the big leagues last year, is the organization's best in-house source of help on that front. He has 16 homers at Triple-A Fresno while hitting .349 through 275 at-bats, and more importantly he is showing improved plate discipline. He walked 19 times and struck out 74 times in 350 plate appearances last year in San Francisco; in Fresno this year he has posted a 52-50 walk-to-strikeout rate in 333 plate appearances.

9. Brandon Wood, SS/3B, Angels

Wood is no longer technically a "prospect" because he has too many big-league at-bats, but he's in his third season in Triple-A and continues to make adjustments, cutting down on his strikeouts and showing the ability to play solid defense in either spot on the left side of the infield. Wood loses out with manager Mike Scioscia, who prefers quicker infielders such as Erick Aybar, Chone Figgins and Maicer Izturis. But the Angels could use another right-handed bat, and Wood looks like a better bet to make an impact than his struggling former minor-league teammate, Howie Kendrick.

10. Jason Heyward, OF, Braves

The Braves' outfield woes are well-documented, particularly those of right fielder Jeff Francoeur. Another in-house answer, Brandon Jones, is in his third year in Triple-A and is homerless this season. Enter Heyward, Atlanta's 2007 first-round pick. He was a non-roster invitee to big-league camp this spring, hanging around through mid-March, and just got promoted to Double-A. It would be a rush job to bring his premium bat speed and right-field tools to the majors to replace Francoeur, but the National League East is wide open, and a jolt from a big bat like Heyward's could separate Atlanta from the pack.

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