The Twins initially targeted Sunday as a possible return date for Mauer -- who is slated to catch on Thursday night with Class A Fort Myers after catching eight innings on Wednesday -- but he likely won't join the team until late next week at the earliest.
"We talked about after the 12th when he came off the 60-day DL, if he was ready, then we'll bring him up here," Gardenhire said. "If he hasn't caught enough and we don't deem ready to do that, we won't do that. We saw that happen in Spring Training when we thought he was ready."
Mauer could also see time with Triple-A Rochester to see better pitching, but at this point the club is more worried about Mauer getting time behind the plate than anything else.
"My concern more for Joe than Triple-A is being able to catch back-to-back-to back games," Gardenhire said. "I think he's caught 22 innings up to this point, and I don't think that's enough catching to say he's ready to start the grind up here of catching four or five games in a row."
Mauer has played only nine games with the Twins this year and last played on April 12, when he caught 10 innings against the Royals.
"He's anxious to get up here and wants to play," Gardenhire said. "He's missed a lot of baseball games. But on the flipside of that, we have to make sure he's ready to get back up here and catch three or four days in a row."