Starting quarterback Wilton Speight went down with an injury in the first quarter after taking an awkward hit on a sack and was out for the remainder of the game.
"I don't think it's anything structural. I think it's soft tissue," Michigan coach Jim Harbaugh said. "But we'll find out more. He's just working through something."
Harbaugh said he did not know how long Speight would be out and said Speight would be evaluated further once the team got back to Ann Arbor.
It was a game full of adversity and injuries for the Wolverines, as Speight came out of the game along with tight end Nick Eubanks and receivers Nate Schoenle and Kekoa Crawford. Purdue was called for two targeting penalties, one of which resulted in the Eubanks injury. When asked if he thought Speight was injured on a late hit, Harbaugh said he didn't see it.
Speight was replaced by backup John O'Korn, who recorded 270 yards passing and one touchdown on the day. O'Korn didn't know he would play as much as he did, but the fact that he did was emotional for the Houston transfer.
O'Korn's former offensive coordinator at Houston, Tony Levine, was standing on the opposite sideline coaching with Purdue. On several occasions, after impactful plays, O'Korn gestured toward the Purdue sideline. Later, he confirmed that was aimed at Levine.
"I honestly don't even remember what I said, but it was an emotional day for me just for things to come full circle after everything I've been through," O'Korn said. "Him being the one responsible for making the decision to bench me at Houston. It was an emotional day. ... But for me, I'm a competitor, and it meant a lot for me to just, if I don't play again for the rest of the year, to be able to go out and beat my former coach was a big moment for me."
O'Korn said there are no hard feelings toward Levine, the two hugged before and after the game, and there is no bad blood. It was simply competition at play, he said, and the two are on good terms.
Michigan left West Lafayette, Indiana, on good terms as well -- with a 4-0 record heading into a bye week.
"We move on with humble hearts and have a happy flight home," Harbaugh said. "Next week we have an improvement week, so we'll set our sights on that for next week, then onward to back to action."