Willingham has been taking fly balls along with the other outfielders in camp, but hasn't played in right field in any game action.
Willingham, 33, has played 693 career games in the outfield, but only 35 of those games in right field.
"He's with the outfielders every day doing drills," Gardenhire said. "We'll get him out there once the games start. We have a long ways to go. We won't know much by drills. We'll know more by games and how the ball is coming off the bat."
Gardenhire said that if Willingham can't make the switch to right field, he could make adjustments with center fielder Denard Span or left fielder Ben Revere.
"I know Ben Revere can move over to the other side in a heartbeat," Gardenhire said. "Span could move over there. We have guys willing to do whatever it takes to win. That's what we are going to do. We're going to try to figure this out in Spring Training. We're going to start out this way and if it looks like it's working OK and he's getting used to that, he'll be out in right field. But if it looks like he's not comfortable in right field, I know the other guys can do it for a fact."