MINNEAPOLIS -- The Twins are planning to wait until Friday to activate catcher Joe Mauer from the 15-day disabled list for the first game of their series against the Royals.

The decision to wait comes from the fact that the roster move to make room for Mauer likely will hinge on the health of catcher Mike Redmond.

Redmond had an MRI on his sore right shoulder, and Minnesota manager Ron Gardenhire said the veteran was available only on an emergency basis for Wednesday's series finale against the Rays.

"There is no damage or anything," Gardenhire said. "He's just had a bit of a sore arm for a few weeks."

The 37-year-old catcher has not played since Saturday due to the sore shoulder, and he's been started on some medication to help battle the soreness. The Twins have an off-day on Thursday, and then Redmond will be reevaluated by team doctors on Friday. Redmond feels he should be ready to play by Friday, but that, of course, is the day the Twins will activate Mauer.

Prior to the news of Redmond's injury, it had appeared that catcher Jose Morales likely would be sent down to Triple-A Rochester to make room for Mauer. But with Redmond's availability in question, the club could decide to keep three catchers or perhaps put Redmond on the 15-day disabled list to get his shoulder feeling closer to 100 percent.

"We're kind of in a little bind here with [Redmond's injury]," Gardenhire said.

When asked about the possibility of going on the disabled list for only the second time in his career -- his last trip to the DL came in 1998, his first year in the big leagues with the Marlins -- Redmond didn't really want to think about it.

"I can't do the 'what-ifs,'" Redmond said. "I'm going to wait and see how it feels on Friday. Obviously if it's not feeling good, I'm going to be honest. I'm always honest. If I think I can play, I can play. If I don't think I can play, I'm not going to go out there and hurt the team."

Although the shoulder has been bothering him for a couple of weeks, Redmond said it didn't stem from the groin injury he suffered on Opening Day against the Mariners on April 6. He said the groin injury hasn't bothered him since the first weekend in Chicago, while the shoulder has been affecting him for most of the season.

"I haven't really been throwing like I'm capable of throwing," said Redmond, who is 0-for-9 in attempting to throw out opposing runners this season. "It's been that way for a while. I just want to make sure I get on some medication, get some things cleared up and get back to being able to play."

The groin and shoulder injuries have kept Redmond from getting the majority of playing time behind the plate, as was expected while Mauer was out. Morales, who got his fourth straight start at catcher on Wednesday night, entered the game batting .375 in 16 contests this season.

But while things haven't gone quite as he planned, Redmond has at least kept his sense of humor.

When asked what was found in the MRI, the veteran catcher couldn't help but to crack a joke.

"They found a Bud Light in there," Redmond said with a laugh. "I guess that's a good sign. It's amazing that they found it. ... It was a longneck."