The Diamondbacks are going to be without a valuable part of their bullpen. (Getty Images)

The Diamondbacks have placed right-hander Josh Collmenter on the 15-day disabled list with "ulcers." The team didn't elaborate in its official announcement, but Collmenter's condition is self-evidently enough to sideline him.

They've replaced Collmenter on the active roster with right-hander Brad Bergesen. The 26-year-old Bergesen has a 4.64 ERA in 399.1 career major-league innings, and this season he's primarily been at the Triple-A level, where he's posted an ERA of 3.86 ERA in 84.0 innings as a starter and reliever.

As for Collmenter, also 26, he has a 4.24 ERA in 74.1 innings this season, but he has an ERA of 1.61 out of the bullpen in 2012.

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