The Twins have already clinched the AL Central Division, so they have the luxury of resting some of their starters before the playoffs begin next week.
"Hardy's going to get it checked out by our doctors," Twins manager Ron Gardenhire said. "It's a lot better than it was on Sunday, but there's still swelling and it's still stiff."
Hardy went 2 for 5 Saturday at Detroit, but was lifted for a pinch runner in the 12th inning in a 13-inning 11-10 loss. That was his first game since Sept. 20 because of migraine headaches.
Thome has not played since Sept. 22 and has had chronic back problems. He took swings on the field Monday, but did not feel well enough to play.
He said returning to Minnesota to receive treatment remains an option.
"Target Field is a great facility," Thome said. "It has the whirlpool and other facilities which we just can't get on the road. We'll talk about it and see if that's the best option. This is something I've dealt with in the past. It's something that has been there in the past. Anytime you have the option — and with the whirlpool — anytime you have that option you have to think about it."
Mauer received a cortisone shot in his aching left knee Wednesday and did not play in the three-game series at Detroit. He took early batting practice Monday at Kauffman Stadium and will likely not play in the Kansas City series as the Twins rest him before the playoffs.
Mauer is hitting .331 in 133 games, while Thome leads the club with 25 home runs in 271 at-bats.