Freshman sensation Zion Williamson was knocked out of the North Carolina-Duke rivalry game with a knee sprain after his Nike shoe blew out during the top-ranked Blue Devils' opening possession Wednesday night. Nike said in a statement that it was "concerned" and wished Williamson a speedy recovery. It said it was "working to identify the issue."

Williamson, widely expected to be the top NBA draft pick,  grabbed his right knee in pain after slipping awkwardly and falling when his left shoe fell apart as he planted hard while dribbling near the free throw line. The blue rubber sole ripped loose from the white shoe from the heel to the toes along the outside edge, with Williamson's foot coming all the way through the large gap. 

"It's a mild knee sprain," Duke coach Mike Krzyzewski said of Williamson's injury after the game, adding that more information will be available on Thursday. "The knee is stable. We don't know how long he'll be out." 

Williamson, the ACC's second-leading scorer at 22.4 points per game and arguably the most exciting player in college basketball, walked off with a slight limp but under his own power before heading back to the locker room with no shoes on his feet.

No. 8 North Carolina took advantage of Williamson's absence to beat the Blue Devils 88-72.

Duke is four years into a 12-year deal with Nike as the exclusive supplier of uniforms, shoes and apparel. The private school didn't disclose terms of the 2015 contract extension.

Nike has had an exclusive deal with the university since 1992. The Big Lead reported that the shoe giant's rival, Puma, fired off a tweet, which has since been deleted, declaring Williamson's injury "wouldn't have happened in the pumas."

A similar Twitter salvo was launched by a Nike shoe designer in 2012. After star Derrick Rose went down with a season-ending injury, Nike's Jason Petrie took to Twitter and suggested that Rose hurt himself because of the Adidas shoes he was wearing.