"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." MLBTRADERUMORS.com
