The NFL says reported concussions rose 58 per cent in regular-season games to the highest number in any of the past four years.
The league issued its concussion data for 2015 on Friday, a little more than a week before the Super Bowl, but did not release any data about total injuries.
According to the NFL, there were 182 reported concussions from 2015 regular-season games, reversing a recent downward trend. There were 115 in 2014, 148 in 2013, and 173 in 2012.
A year ago, the league touted those decreases as a reflection of players changing the way they play football.
NFL Senior Vice-President of Health and Safety Policy Jeff Miller says Friday the league is trying to figure out why concussion numbers rose so much this season.
