Girardi spoke on Tuesday at the Baseball Assistance Team dinner in New York, where he received the inaugural Bobby Murcer Award on behalf of the Yankees. The club acquired Granderson in December to play center field, but Melky Cabrera has since been traded to the Braves and Gardner's value is as a pure center fielder.
"That's something that we'll discuss as we get down to Spring Training," Girardi said. "You kind of wait to see what's going to happen here, if we do sign another bat and another outfielder, and how that really adjusts everyone's playing time.
"I'm not really locked into anything. We're going to do whatever makes our team the best, but until we have that full team, it's kind of hard to make that decision."
Yankees general manager Brian Cashman has said that his remaining priority this winter is to acquire a right-handed-hitting outfielder who could help ease some of the load off Gardner, who is tentatively penciled in as New York's starting left fielder.
But Girardi considers Granderson and Gardner interchangeable defensively, because the dimensions of Yankee Stadium require that both the left fielder and center fielder be able to race balls down often.
"When you look at our outfield, right field is the short porch, and left and center are the areas to cover ground," Girardi said. "I think wherever we put either one of them, they're going to cover a lot of ground when they're out there.
"If Gardy is in left, he's going to cover a lot of ground and that's going to be helpful. Our field is built to where you want your left fielder and your center fielder to cover a lot of ground."
Granderson played just 22 career games in left field with the Tigers, and has not appeared there since 2007. At the time of his acquisition, Cashman noted that Yankees scouts expressed some concern with routes he took chasing fly balls in September, and Girardi said that Granderson could handle left field.
"I think Curtis Granderson, as skillful as he is, could play anywhere in the outfield," Girardi said. "That's something that he could do. But right now, we're not sure exactly what our club is going to be, so it's hard to say what everyone is going to be."
Girardi spoke on a day when Cashman all but closed the door on Johnny Damon's potential return to the Yankees, and Girardi also acknowledged that he didn't see a deal getting done. The only remaining course for Damon with the Yankees appears to be accepting a deal well below the $13 million he earned in 2009, and Girardi said if that unlikely event happens, Damon would be welcomed back.
"I think players that come back want to win," Girardi said. "I think Johnny wants to play for a while, so it would be in Johnny's best interest to have a good year and see if he could parlay that into a bigger deal the following year or the next year. I would not have a concern about Johnny coming back, because I think Johnny loves to play and Johnny loves to win. He's going to do whatever it takes."
Girardi also mentioned that he is comfortable heading to Spring Training with Francisco Cervelli as Jorge Posada's backup catcher. Jose Molina remains on the free-agent market, but New York has not expressed interest, believing that Cervelli is capable of handling the role.
"I think it's a job that he can do," Girardi said. "He played at a very high level for us last year, and I think he learned a lot. He got some great experience. I think it's a job that he can handle."
Girardi will have one more public appearance during a busy week for him, teaming with Yankees legend Bernie Williams on Saturday for a Hillside Food Outreach event in New Rochelle, N.Y. Girardi said that he did yet not know if Williams would be joining the Yankees this spring as a guest instructor.
"I love having Bernie around," Girardi said. "He has not talked about that, but if he wants to, I know it's something we'll definitely talk about."
Bryan Hoch is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.