CHICAGO - Joe Mauer's latest injury was almost healed Monday, but Justin Morneau was hurt again.

On and on it goes for the 2011 Twins.

Mauer hasn't been in the lineup since last Tuesday, when he hurt his neck while playing first base, trying to make an over-the-shoulder catch in right field against Baltimore.

"What happened was, I hyperextended my neck and sent my muscles into a spasm," Mauer said before the Twins' 3-0 loss to the White Sox on Monday night. "So I'm just trying to get past that soreness and get to where I can move my neck and get out there and play."

Mauer took batting practice and fielded grounders at first base, where playing time might be available because of Morneau's latest injury.

Morneau was sliding and diving all over the field Sunday against Detroit. He landed awkwardly on his left shoulder trying catch Alex Avila's double down the first-base line in the second inning.

"He woke up real stiff with his left shoulder, so we're going to give him a day without swinging," trainer Rick McWane said.

Morneau was getting treatment in the training room and unavailable for comment.

"You play the game the right way, and he was doing that [Sunday]," manager Ron Gardenhire said. "Sometimes you land a little funny, and we'll see what happens. Hopefully he'll be playing [Tuesday]."

Nathan prefers to stay Twins closer Joe Nathan has veto power over any trade with 10-and-5 rights -- 10 years in the majors, five with the same team. He said he hadn't heard if he's been placed on trade waivers, something that would have to happen for him to be moved.

Nathan said he's open to a deal but would prefer to stay with the Twins. "Obviously, everybody wants to be involved in meaningful baseball in September for sure," he said. "But first and foremost you want to do it here."

Nathan has converted his past eight save chances and posted a 2.21 ERA in his past 22 games. With Brian Wilson hurt, the Giants claimed Padres closer Heath Bell but didn't make a deal. Otherwise, there haven't been many rumblings of contending teams for a closer.

Nathan is owed $2 million for the rest of this year and has a $12.5 million option for next year, with a $2 million buyout. So, at a minimum, Nathan would cost another team $4 million, which limits his trade value.

Etc. • Back from a strained oblique, shortstop Tsuyoshi Nishioka made his first start since Aug. 19. He reached base all three times Monday with a single and two walks against Mark Buehrle.

• Michael Cuddyer also returned after missing two games because of a bruised left wrist. He went 0-for-4 with a strikeout.

• Alexi Casilla (strained hamstring) began a rehab stint with Class A Fort Myers on Monday. He was originally scheduled to go to Class AAA Rochester but had trouble getting to Buffalo, N.Y., because of Hurricane Irene.