Timberwolves guard Jimmy Butler's sore back kept him out of most of practice Sunday and could keep him out of Monday's game against Portland at Target Center.

"He didn't do much today," Wolves coach Tom Thibodeau said after Sunday's short practice. "Just getting treatment. We'll see how he is [Monday]."

Citing back spasms, the Wolves listed Butler as questionable for Monday's game.

Butler's back appeared to tighten up in the second half of Saturday's loss to Phoenix. Butler briefly left the court, getting some treatment in the locker room, before returning to the bench.

Still, he played. He re-entered the game early in the fourth quarter, playing the final 10:05. But even when he was in the game, he appeared to be laboring.

"I could tell his back was bothering him," Wolves forward Taj Gibson said after the game. "He was in a lot of pain. Every time he was trying to move, every time he was trying to cut he was in a lot of pain. He tried to thug it out, being the warrior that he is."

With the Wolves down five with 4:08 left, Butler's steal and end-to-end basket spurred a 6-0 run that put the Wolves up a point with 1:22 left. But, after Isaiah Canaan's three free throws with 6.1 seconds left, Butler had two chances to score. He missed a driving layup with 1.7 seconds left. Then, off an inbounds play, Butler missed a 16-footer with 0.3 seconds left.

Thibodeau said he hadn't decided who would start in place of Butler should the back keep him out of action. When Butler missed two games because of illness early in the season Thibodeau inserted Shabazz Muhammad into the starting lineup. But Muhammad has not been a part of Thibodeau's rotation of late; he hasn't appeared in the past seven games.

Too much charity

A film review of the game confirmed what Thibodeau thought immediately after Saturday's loss: The Wolves are committing way too many fouls on jump shots. Saturday the Wolves committed three fouls on three-point attempts, including Jeff Teague's foul on Canaan with 6.1 seconds left in the game. In all, the Suns got 35 free throw attempts off 19 Wolves fouls. Both the 35 attempts and 31 makes were season highs for Wolves opponents, topping the 27 makes and 32 attempts Philadelphia got while beating Minnesota on Tuesday.

"They are calling it tight on jumpers," Thibodeau said of officials. "And you can't foul or appear to foul. That's the big thing. And then we're whacking down. Late in the game, we're coming down. We did it in the Philly game, and we continue to do it. That's discipline. Our bigs have to play with verticality. When we do it, we're good. When we whack down, we're bad."

Etc.

• Thibodeau said he thought Butler was fouled on his drive for a basket with 1.7 seconds left in the game. "Yes," he said. "The way I saw the play, the [defender's hands] were up, but there was a wipeout with the body. So, sometimes it goes for you, sometimes it doesn't." On the NBA's 2-minute report the league said it was a correct non-call.

• The 2-minute report also reiterated that the foul call on Canaan's three-pointer was the correct call.

• Rebounding has also been a problem of late. The Wolves were outrebounded by 21 Saturday, the biggest margin since Thibodeau began coaching the team.