The freak injury during one of the US college basketball season's marquee games immediately sparked debates about everything from the shoe manufacturer to insurance issues and whether the likely NBA lottery pick should risk his professional future by continuing to play for Duke.

Coach Mike Krzyzewski said after Duke's loss to North Carolina on Wednesday that Williamson sprained his right knee and didn't know how long he will be out.

By Thursday morning, Nike, which manufactured the shoes Williamson was wearing, also was feeling the impact of the injury.

The company's stock price was down about one per cent, or 97c, to $US83.87 during trading as the sportswear giant became the target of online ridicule.

"Shoes have failed before, but not as visibly," Matt Powell, a senior industry advisor for sports for the NPD Group, said.

Playing before a crowd littered with celebrities - from Spike Lee to former President Barack Obama - Williamson was hurt in the opening minute of the game as his Nike PG 2.5, from Oklahoma City Thunder star Paul George's signature sneaker line, tore apart.

The 280-pound Williamson is one of the most powerful players in the game, and he tried to plant with his left foot as he lost his right foot was slipping.

The blue rubber sole ripped loose from the white shoe and Williamson's foot came all the way through the large gap.

He ended up in an awkward-almost-split, clutching the back of his right knee. He walked to the bench and a few minutes later headed to the sheds.

The injury also set off a fresh round of debate about whether Williamson - the possible No.1 overall pick in the NBA draft, should he leave Duke after his freshman season - would be wise to end his college season in an attempt to avoid an injury that could jeopardise his pro career.

"I couldn't do that to my teammates," Williamson had said. "Again, thank you for, like, seeing the confidence in me and the type of player I can become. But I love college too much to stop playing. I wouldn't give this up."

Now that he's actually hurt, it's unknown if his feelings have changed.

Australian Associated Press