Earlier, Girardi hinted that Rivera could make his debut against the Dominican Republic's World Baseball Classic entry on Wednesday. Rivera will not accompany the Yankees when they play the Cardinals and Marlins on Thursday and Friday in Jupiter.
Rivera threw a simulated inning on Sunday and said that he feels prepared to pitch in a game.
"I think that we are ready to do that," Rivera said.
Rivera hasn't pitched in a game since April 30 of last season, when he shut down the Orioles in a scoreless ninth inning at Yankee Stadium for career save No. 608. Rivera injured his right knee in a batting practice mishap on May 3 in Kansas City and underwent surgery in June.
"I'm waiting for 10 months, I can wait another few days," Rivera said on Sunday. "I just wait patiently. It will be exciting when I'm there, but I've been waiting for a long time, so no rush."
Additionally, Girardi added that Derek Jeter could play on Sunday, which would be the Yankees captain's first appearance in a game since he fractured his left ankle in Game 1 of the American League Championship Series.
Jeter said this week that he has yet to run the bases at maximum effort. The Yankees plan on using Jeter as a designated hitter when he does begin playing in Grapefruit League games, though they expect him to be ready to play shortstop by Opening Day.
"I've been more under the impression we take it day by day and see where he's at," Girardi said. "He's doing well. He's progressing the way we want, so we'll see where he is this week. We should know in the next few days if [Sunday is] a real possibility."
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.