"It's pretty simple here -- he came in with a stiff back and there's no sense of him playing in this weather," Gardenhire said. "[The trainers] said to give him a day here and we'll go from there. I listen to what they say."
Earlier in the day, it was raining at the ballpark, and there is another threat of rain later in the evening.
Mauer has been on fire recently, as he's on a 14-game hit streak. He's batting .446 (25-for-56) with 11 doubles and 11 walks over that span to raise his batting average to .349 with a .431 on-base percentage.
He didn't take batting practice before Friday's game and his return for Saturday is still questionable.
"We're hoping this is short-term," Gardenhire said. "We're hoping he can play tomorrow."
Rhett Bollinger is a reporter for MLB.com. Read his blog, Bollinger Beat, and follow him on Twitter @RhettBollinger. This story was not subject to the approval of Major League Baseball or its clubs.