Nova will throw a bullpen session on Tuesday, but New York is "just going to kind of go day by day here to see" what his role will be.
"It's possible he could get another start here at some point," Girardi said. "I'm not taking anyone out of the rotation, but we're in a long stretch here of 20 games, so it's possible we might put him in there just to give the guys an extra day that way."
The Yankees sent Nova to Triple-A Scranton/Wilkes-Barre largely so that he could remain a starting pitcher, but Girardi said he will be available out of the 'pen in New York.
He won't be available on Tuesday or Wednesday, and probably not on Thursday either, but after that, Girardi will have him available for relief duty.
"We'll keep him in the bullpen probably for that," Girardi said, "just in case of emergency and then we'll see where it goes. There's no exact plan."
Bryan Hoch is a reporter for MLB.com. Follow him on Twitter @bryanhoch and read his MLBlog, Bombers Beat. David Wilson and Josh Vitale are associate reporters for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.