The do-it-all junior forward will miss the remainder of the season after tearing the anterior cruciate ligament in his right knee.
The injury occurred during the first half of No. 3 Purdue's 59-58 win over Minnesota on Wednesday. Purdue made the announcement after Hummel underwent an MRI examination on Thursday afternoon.
Hummel injured his knee on a drive to the basket in the first half. He fell to the floor in pain, clutching his knee, and couldn't put weight on his leg as he was helped off.
"Injuries are a part of the game, but this is obviously disappointing on multiple levels because of everything Robbie Hummel has done for this program both on and off the court," Purdue coach Matt Painter said in a statement. "As he begins his recovery and rehab, Robbie will continue to provide integral leadership as we pursue our team goals down the stretch."
Reaching those goals -- winning the Big Ten title, gaining a No. 1 seed in the NCAA tournament and reaching the Final Four in Indianapolis -- will be more difficult. Hummel ranks second on the team with 15.7 points and 6.9 rebounds a game.
Hummel's value always has gone beyond statistics.
"Rob does something for us offensively and defensively that balances our team," Painter said last season while Hummel was out with a back injury. "He's a facilitator. He moves the basketball, he makes the extra pass, he gets the ball inside. ... Some of the basic things that don't show up in a box score is what we miss."
The Boilermakers (24-3, 12-3 Big Ten) are on a 10-game win streak, lead the Big Ten and are enjoying their highest national ranking since 1994. Now, Purdue heads into Sunday's showdown with Michigan State without one of its stars.
Purdue struggled last season while Hummel recovered from the back injury. In Purdue's first 11 Big Ten games last season, the Boilermakers were 6-1 with him and scored 68 points a game while allowing 60. Without him, Purdue was 1-3 and averaged 60 points while surrendering 63.
When he returned to near full strength at the Big Ten tournament, he lifted the team by averaging 16 points and 9.3 rebounds per game and received the most outstanding player award.
Hummel had been healthy all season until Wednesday night. Purdue led 26-14 when Hummel drove to the lane and felt his right leg give slightly as he tried to plant with 7:11 left in the half.
"Obviously, we missed him, because we had a good start to the game," Painter said after the game. "He gives us a balance to the game. He can go inside or outside, and he's a good passer. When we lost him, it hurt us a little bit."
The Boilermakers showed they can win without him. Purdue led 26-14 when Hummel was hurt, then fell behind in the second half before rallying to win.
"They did a great job on making shots when they had to, getting the rebound, and they made some clutch shots down the stretch," Minnesota coach Tubby Smith said after the game. "That is what championship teams do."
Information from The Associated Press was used in this report.