Bettman on hockey and CTE: 'No evidence yet that one necessarily leads to the other'

NHL commissioner Gary Bettman says there is no proof that playing hockey causes chronic traumatic encephalopathy, a degenerative brain disease.

"From a medical and science standpoint, there is no evidence yet that one necessarily leads to the other," Bettman told reporters at the United Center in Chicago on Thursday.

"I know there are a lot of theories, but if you ask people who study it, they tell you there is no statistical correlation that can definitively make that conclusion," he added.

The commissioner was reportedly ordered to testify in a concussion lawsuit filed by 60 former players earlier this month, and the league may have to pay millions of dollars to produce thousands of medical records for the case.

Bettman told reporters Thursday that the NHL plans to vigorously defend the lawsuit.

The family of former NHL defenseman Steve Montador is reportedly planing to file a lawsuit against the NHL after the late blue-liner was diagnosed with CTE following his death in February.