Robinson went to the locker room with the team's trainer after landing awkwardly and limping to the bench shortly after halftime. He did not return, although he tested his ankle by jogging on the sideline during a timeout.
"He did something with that ankle," coach John Beilein said after the game. "I'm not sure what it is. He tried to run down the hallway. He tried to run on the sideline. ... Why make it worse?"
Michigan will host Northwestern on Sunday, and Beilein said he's not sure whether Robinson will be available. He also said he's concerned about Robinson's ankle potentially swelling on the flight back to Ann Arbor.
"We've got a lot of work to do to get him rehabbed and get him ready for Sunday," he said.
It's another challenge for a Michigan squad that lost preseason All-American Mitch McGary last week. McGary is scheduled to have back surgery and could miss the rest of the season.
Beilein said he tries to focus on the players who are available.
"You don't think about what you don't have," he said.