A 16-year-old Canucks devotee says she was sticking up for Ryan Kesler when she got hit in the head by a drunken Sharks fan during Wednesday night's hockey game in San Jose.

Maggie Herger claims the incident occurred while she was wearing a Canucks jersey to HP Pavilion, tweeting that she "got punched in the head for being a nucks fan (sic)" and defending the team's alternate captain.

On Friday morning, she reported having trouble sleeping: "Ouchie :( can't sleep, the whole back of my head feels like a huge bruise #notfun," she wrote.

The Sharks issued a statement Thursday confirming that arena staff attended to a fan in need of medical assistance during the game's second period.

Police then went to the girl's seat and talked to her alleged assailant, who claimed they struck her accidentally while cheering for a Sharks goal.

"Upon being interviewed, others seated in the area of the incident did not report seeing the contact between the parties involved," Sharks Sports & Entertainment said.

Herger, a Canadian living in Discovery Bay, Calif., told the San Jose Mercury News she suffered a concussion and had to be taken away from the arena in an ambulance.

She also told the paper she underwent surgery fours years ago to remove a brain tumour, and received an uplifting visit from Canucks players during her recovery.

Police say they are investigating the incident, but have made no arrests.