MILWAUKEE – Now we know why Byron Buxton struck out four times against Chris Sale on Wednesday.

"He couldn't hold the bat," Twins outfielder Torii Hunter said.

The Twins on Friday placed Buxton on the 15-day disabled list with a sprained left thumb — but manager Paul Molitor said the speedy outfielder could be out four to six weeks. Buxton's first tour of Major League Baseball comes screeching to a halt and extends his battle with injuries that has lasted over a year.

"Disappointed for him," Molitor said. "He has been through a whirlwind the last couple of weeks. Now he's been set back by injury, unfortunately. I reached out to him and said, 'Hey, you have to weather this storm like anything else and hopefully come out better on the other end.' "

Buxton injured the thumb during Tuesday's 6-2 loss to the White Sox when he was thrown out trying to steal second base. His left thumb got caught as he began his headfirst slide into the bag.

Molitor said he was told by head trainer Dave Pruemer that Buxton had a bruise on his thumb but didn't think much of it because it happens to players who dive into bases.

"He thought it was just swollen and would take a day or two to calm down," Hunter said.

The left hand, the bottom hand for righthanded hitters, is crucial in holding the bat tightly. The top hand can slide off, but not the bottom, and Buxton had trouble swinging on Wednesday.

The Twins conducted tests and found a slight tear in the ligament.

"I talked to the guy all Wednesday night, and he was so disappointed," Hunter said. "He feels like he let the team down. I told him it is part of baseball because you play hard."

Some Twins players didn't realize Buxton was out until after the team plane landed in Milwaukee on Thursday night. Buxton is batting just .189 through 11 games with two walks and 15 strikeouts, but everyone stopped what they were doing to watch him hit because they wanted to see baseball's top prospect in action.

Now they have seen what has delayed his ascension to the majors. Since spring training in 2014, Buxton has sprained his left wrist twice, suffered a concussion and broken his left middle finger.

"I don't want to get into a debate on if he is injury prone," Twins General Manager Terry Ryan said. "He's certainly had his share all right."

Ryan had one problem. Buxton didn't get treatment on the thumb before Wednesday's game.

"That's the one thing I disagree with or am disappointed in," he said.

Buxton will remain in the Twin Cities, working with Twins rehabilitation coordinator Lanning Tucker, before he's ready to head down to Fort Myers, Fla., to continue rehab and work in more baseball-related activities.

It's another setback for the promising Buxton, one that he'll have to learn from. If he is going to slide that way, he can hold his batting gloves in his hands when he runs, which lowers the risk of jamming a finger or thumb when sliding. Or he could slip on a glove that resembles an oven mitten to protect his hands.

Or he can change the way he slides.

"I'll tell you one thing," Hunter said. "He won't slide like that ever again."