DETROIT -- Sometime during Joe Mauer’s later days at catcher, before he moved to first base, then-Twins manager Ron Gardenhire and his staff apparently toyed with the idea of putting him at third base, a position many former catchers have handled. To get an idea of how it would go, they had him do some early work there.

“I had Mauer taking ground balls in Cleveland,” Gardenhire recalled, “and I was standing behind, watching him. And then he missed one, [the ball] hit me in the knee and I said, 'OK, Joe, this is not the place.'”

Mauer then moved to the other side of the diamond, found a comfort zone, and spent the final five seasons of his career as the Twins' primary first baseman.

That type of late-career move wasn’t the motivation that Gardenhire and the Tigers had, he said, when they talked with Nicholas Castellanos last year about giving first base a shot. 

“The conversations have always been about: It's just another feather in your cap if you learn to play first base,” Gardenhire said. “That means more options for this team, more options for any team, if he becomes a free agent or whatever down the road. 

“Ultimately, he's a big guy; he's got a wingspan, an easy target. Ultimately, that's something, and I told him, 'Maybe you should do this.' You know he can play the infield. He played third base. He takes ground balls at shortstop every once in a while. He's got natural movement. It's not something that's a negative. It's just another positive, and that's kind of the way we explained it.”

Castellanos, having been moved from third base to right field late in the 2017 season following Jeimer Candelario’s arrival, said earlier this week that he would’ve been willing to make the move if the Tigers were willing to commit to a long-term extension. Without that, he preferred to keep his focus on right field in his final season before free agency.

• Castellanos on rumors: 'My job is to play'

"I told them: If you offer me an extension, if you show me that I am a piece of the future, I'll play first,” Castellanos said Friday. “I'll even throw bullpens for you. But give me that security. …

"So last year, when obviously there was no commitment toward me, I chose: I just want to stick to right and try to be as good as I can in one spot. That was the first time where I said no. I've said yes a lot. So last year, it was just like, 'No, not right now.'"

Gardenhire said he understood.

“He's right in the fact that he's been moved a bunch and he's trying to play right field,” Gardenhire continued. “And he's right in the fact that the longer he stays out there, the better he's going to get. But also down the road, if he can play first base, that lengthens your career. It does all kinds of good things for him, because that's another feather in his cap on a position that he can play. Whether he'll ever do that, I don't know. I don’t know if that’ll end up being on his plate or not.

“I told him I'm happy. He had a rough play last night, but for the most part, he's played really [well in the] outfield, played really well running the ball down, hitting the cutoff man, the whole package. I've been really happy with his play.”

Cabrera to play first base in Pittsburgh

The Tigers have one more trip to a National League park this season with next week’s two-game series in Pittsburgh, which means two more games without a designated hitter. For one of those games, they’ll likely have Miguel Cabrera back at first base for the first time in nearly three weeks.

Cabrera was out of Sunday afternoon’s lineup after playing the previous five days. With an off-day Monday night, he’ll have two days of rest to prepare for Tuesday’s series opener in Pittsburgh. 

“We talked about him playing first base in the first game, and then the next game [Wednesday], not playing at all,” Gardenhire said. “We’ve got time to give him breaks off his legs.”

The Tigers have essentially made Cabrera a full-time DH in the two weeks since doctors diagnosed him with what the Tigers called "chronic changes" in his right knee due to attrition. But Cabrera has looked and felt stronger while wearing a knee brace.

“He’s got a brace, and he says he feels good with it,” Gardenhire said. “So putting him out there at first base in the National League game to keep his bat in the lineup is one way to do it. But I’m going to give him a couple of days [off] here leading up to it.”