"I would think August is probably realistic," Girardi said. "You've got to build him up. That's the problem."
Pineda sustained the initial setback while throwing a simulated game in Tampa, Fla., in April, attempting to stay sharp while serving a 10-game suspension levied after he was ejected from a game at Fenway Park for having pine tar on his neck.
"It really is [disappointing]. I don't think we're going to have to limit his innings," Girardi said.
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.