May picked up the ball and scooped it to first baseman Kennys Vargas for the out, but after a brief consultation with team trainers, he exited the game. May was later diagnosed with a right elbow contusion and is considered day-to-day after X-rays were negative, the team announced.
May, who ended up pitching 3 1/3 innings and giving up two runs on three hits and striking out five batters, was replaced by reliever Tim Stauffer.
Doug Miller is a reporter for MLB.com. Follow him on Twitter @DougMillerMLB. This story was not subject to the approval of Major League Baseball or its clubs.