According to Jesse Temple at MLB.com, the White Sox have acquired RHP Tony Pena from the Diamondbacks for 1B prospect Brandon Allen.
Pena, 27, had been serving as a late-inning reliever for the D'Backs, where he's amassed a 4.24 ERA and 26/11 K/BB ratio in 34 innings. Pena is cheap and under team control through 2012.
Allen is a 23-year-old prospect with power. He's struggled since being called up to Triple-A earlier this year, putting up a .584 OPS in 13 games so far, but he mashed in the minors last year, putting up a .972 OPS in 153 Double-A at-bats.
This looks like a decent return for both teams. Pena has allowed quite a few more hits than usual this year, but sports a .352 BABIP that could be due for regression. He could be useful in the back end of the bullpen. John Sickels at Minor League Ball rated Allen the fourth-best Sox prospect before the season. This deal pretty much solidifies the Diamondbacks as sellers, so it'll be interesting to see if they move any more pieces before the deadline.
