Athletics manager Mark Kotsay revealed that Wood was bothered by a shoulder injury during his start in Sunday's 8-4 loss to the Mariners, Martin Gallegos of MLB.com reports. "Alex has been grinding," Kotsay said. "He hasn't felt great. He's been able to make every start. But you saw a little drop in velo and his slider wasn't as sharp. He gave us everything he had for two innings."

Wood gave up five runs (one earned) on four hits and one walk while striking out one batter across 60 pitches before he was pulled from the contest, with Kyle Muller coming on in long relief behind him and covering the ensuing four innings. As Kotsay noted, Wood's velocity was well down Sunday compared to his season-long average of 90.5 miles per hour, as his sinker averaged just 88.6 mph on the afternoon. Kotsay suggested that Wood would be sent in for further evaluation before a decision is made on whether the lefty will be able to make his next start, which would fall next weekend in Kansas City.