This is from SI.com. The A's are ranked first in injuries suffered but the summary is GREAT:

"The big problems: The A's have one of the deepest pitching staffs in baseball, and they've needed every inch of it to stay afloat in the middling American League West. Rich Harden, Joe Kennedy, Esteban Loaiza and Justin Duchscherer all are sitting on the disabled list right now. Closer Huston Street was nursing a muscle strain in his chest earlier this season, though he never made it to the DL. The A's have had some hurting hitters, too, including Milton Bradley, Frank Thomas and Eric Chavez.

How they've handled it: Brad Halsey and Kirk Saarloos have filled in as starters with less-than-mixed results (3-4 between them, with a combined 5.06 ERA). Still, it's a measure of the team's pitching depth that the staff still is ranked fourth in the AL with a 4.47 ERA. That has kept the A's around .500.

Bottom line: Most of the pitchers should be back by the end of June. In the AL West, that makes the A's huge favorites."