Puk was placed on the 10-day injured list due to a strained left biceps, retroactive to April 7.
Puk had a strong performance in his first relief appearance of the season Monday, as he allowed one hit and three walks while striking out four in 3.1 innings. However, he apparently sustained an injury and will miss time as a result. It's not yet clear when Puk will be able to return to game action, but right-hander Deolis Guerra's contract was selected by Oakland in a corresponding move.