Gray was injured in the fifth inning of last night's 3-0 loss to the Detroit Tigers in Game 5 of the American League Division Series.
He was hit in his non-throwing hand by a ball off the bat of Tigers first baseman Prince Fielder. Gray continued to pitch into the sixth inning.
Gray, 23, gave up six hits and three runs after getting the start over veteran Bartolo Colon.
“The guy’s got a bright future, plain and simple,” A's reliever Grant Balfour said about Gray. “He has great stuff, he’s a great competitor. Obviously he went out there, threw eight scoreless [innings in Game 2]. They handed him the ball tonight for that reason. I don’t know if he felt any pressure from that thinking he had to go out and do that again, I don’t know. I still think he threw the ball pretty well.”