MINNEAPOLIS -- Manager Ron Gardenhire admits that it will be a difficult decision when it comes time to send either Rene Rivera or Drew Butera to Triple-A Rochester when Joe Mauer returns next week.

"Oh, absolutely," Gardenhire said when asked if it will be a tough call. "It means both of them are doing OK, so when Joe comes back, sure, we'll have a tough decision. They've both done their parts and they continue to, so it won't be easy no matter which way we go."

Both Rivera and Butera have been swinging the bat well lately, having combined for a .319 batting average over the last 14 games entering Sunday's series finale against the Rangers.

"We've kind of had a good system," Gardenhire said. "We've gotten good production from both of our catchers, kind of mixing and matching [them]. Both of them have been swinging better."

Rivera, who is hitting .208 with a .276 on-base percentage, got the start on Sunday, with Butera, batting .174 with a .207 on-base percentage, on the bench.

Mauer to stay in Florida until joining Twins

MINNEAPOLIS -- Manager Ron Gardenhire said on Sunday that Joe Mauer will not head to Triple-A Rochester as part of his rehab process and will remain in Fort Myers, Fla., before possibly rejoining the Twins on Thursday or Friday.

Mauer is scheduled to catch on Sunday and Monday with Class A Fort Myers, and on Tuesday could either catch or serve as designated hitter, depending on how he feels.

"He's going to stay in Florida," Gardenhire said. "It's a good situation for him. They have all the things they need down there, which is similar to here."

Gardenhire wouldn't confirm that Mauer will back with the Twins on Thursday, but Mauer likely have nothing to prove by then, as he caught three straight games earlier this week and could do the same over the next few days.

Mauer, who has been out since April 12 with bilateral leg weakness, also will have a chance to see Major League-caliber pitching when he goes up against Joe Nathan on Wednesday.

"Nathan wants to throw to live hitters, so we'll give him a really live hitter," Gardenhire said with a smile.

Thome to start rehab work on Monday

MINNEAPOLIS -- Eligible to return from the 15-day disabled list on Thursday, designated hitter Jim Thome will begin rehab work in Fort Myers, Fla., on Monday.

Thome, sidelined since June 2 with a strained left quadriceps, has made progress over the weekend since receiving an epidural on Friday. Before the Twins' series finale with the Rangers on Sunday, Thome even took some swings in the cage.

"I'm feeling good," Thome said. "I swung and had no issues today. Everything went good."

Manager Ron Gardenhire said before Sunday's game that if everything went well, the club would send Thome to Florida.

"He said he would really like to get to Florida and start getting in that heat and start doing his rehab down there and get back to swinging," Gardenhire said. "He likes that program down there because it's controlled pretty well, but he can get a lot of work in because there are so many bodies down there that are willing to try to do something."

Until he begins working in Fort Myers, though, Thome won't know whether he'll be ready to return to the Twins when he becomes eligible on Thursday.

Even if it takes Thome a few extra days to return, the Twins should have a pretty formidable lineup when he does, with Joe Mauer and Tsuyoshi Nishioka expected back from the 60-day DL in the next week.

"I think it's exciting, yeah," Thome said. "Especially with as hard as those guys have worked down there, Nishi and Joe, and the rest of the guys here obviously have done a great job lately. So it's kind of exciting to see where our team could go."

Morneau, others making progress in recovery

MINNEAPOLIS -- Hand specialist Dr. Thomas Varecka has not yet seen the MRI taken of Justin Morneau's left wrist, but that should not delay Morneau's scheduled return.

The MRI showed some fluid but did not reveal any structural damage. Morneau may receive a cortisone shot at some point, but he is expected back in the lineup on Tuesday after sitting out Saturday and Sunday and the Twins' off-day on Monday.

"[Varecka] probably will see it [on Monday]," said Twins head trainer Rick McWane.

McWane also gave updates on the rest of the injured Twins, though there are no major changes for any of them.

Relievers Kevin Slowey (abdominal strain) and Joe Nathan (elbow soreness) continue to work in Fort Myers, Fla., at extended spring training. Slowey was scheduled to throw off a mound on Sunday, and Nathan is set to face hitters on Monday.

Tsuyoshi Nishioka (fratured left fibula) and Glen Perkins (strained oblique) are with Triple-A Rochester in Toledo, with Perkins having thrown a scoreless first inning on Saturday, allowing one hit. Nishioka was scheduled to play on Sunday, and Perkins will throw two innings on Tuesday night in Toledo.

Nishioka is expected to return sometime this week, and Perkins could be back soon as well.

Center fielder Denard Span, on the seven-day DL with a concussion, is "getting better," McWane said.

Eligible to return on Tuesday, Jason Kubel continues to feel better every day.

"He's still doing well hitting, [but] he's still a little bit sore running around," McWane said. "We're just progressing him as he tolerates."