"I talked to him today to make sure that he was feeling OK and he said he didn't quite feel 100 percent," Girardi said. "I said, 'Look, this isn't something we want to mess with, so let's take a step back, get you evaluated and see where you're at.'"
Girardi said that he expects Phelps to have tests performed on the forearm. Phelps is 6-5 with a 5.01 ERA in 18 games (12 starts) for New York this season, and the Yankees had been expected to reinstall him either in their rotation or bullpen shortly.
"He just said it didn't feel 100 percent," Girardi said. "For a player to say that, we just said, 'You know what? You're not going to pitch.'"
Bryan Hoch is a reporter for MLB.com. Follow him on Twitter @bryanhoch and read his MLBlog, Bombers Beat. This story was not subject to the approval of Major League Baseball or its clubs.