Right-hander David Phelps is scheduled to start Thursday's game against the Pirates at Steinbrenner Field, and right-hander Adam Warren will take the mound Friday against the Tigers at Joker Marchant Stadium in Lakeland, Fla.
Girardi said he expects to use five or six pitchers in each of the first few games.
Nuno, Phelps and Warren are in the mix for the Yankees' fifth-starter job, a competition that also includes right-hander Michael Pineda.
Adam Berry is a reporter for MLB.com. Follow him on Twitter at @adamdberry. This story was not subject to the approval of Major League Baseball or its clubs.