FORT MYERS, Fla. -- One day after swinging a bat for the first time in nearly five months, Twins catcher Joe Mauer couldn't take the smile off his face.

Not only had he been able to take 25 swings off a tee in the batting cage on Monday, his first activity with a bat since the Twins' 1-0 loss in Chicago on Sept. 30, but he did so without any discomfort in his torso.

spring training
cactus league
grapefruit league
Even more importantly, Mauer said, he didn't feel any discomfort when he woke up on Tuesday morning either.

"I don't feel any different from yesterday, which is good," said Mauer, who underwent surgery on Dec. 22 to eliminate a kidney obstruction. "It was only 25 swings off the tee but it felt pretty good to have a bat in my hand again."

Mauer's recovery from kidney surgery has been a day-by-day process, with the catcher just trying to show slight improvement every day. So far, Mauer said, things have been moving along smoothly the first week of camp.

Along with swinging a bat for the first time, Mauer has also been intensifying workouts in the gym over the past two days. He's begun doing some light agility drills under the direction of strength and conditioning coach Perry Castellano. But Mauer said he has yet to do much running, which he feels will be the next big test.

"I just have to feel comfortable moving around again and trusting everything," Mauer said.

The All-Star catcher took another step in his progress on Tuesday by taking flips in the batting cage. And with every little step, Mauer can see himself getting closer to being back on the field with his teammates.

"I'm starting to do more baseball activity, which is a sign that I'm getting closer," Mauer said. "I've made a lot of progress this past week. It's definitely encouraging."