A former Ohio State star has decided to retire from football at a young age due to concussions.

Joshua Perry, a member of the Seattle Seahawks and ex-Buckeye star, announced Monday that he will be retiring from the game, citing concussions as the primary reason behind his decision.

He made an announcement via Twitter:

In his message, Perry says he’s had six documented concussions and that it didn’t come from a huge contact play.

I’ve recently sustained my 6th documented concussion. It wasn’t from a high velocity, big contact play. It was a very pedestrian thing, and that was a huge concern to me. The last thing I want to do is put the health of my brain and my future wellbeing in jeopardy over a game and a paycheck.

Perry was Ohio State’s leading tackler in 2014, racking up 124 stops on the team’s path to a national title. He was a fourth-round pick in the 2016 NFL Draft, getting selected by the San Diego Chargers. He also had stints with the Indianapolis Colts and the Seahawks.

Perry retires with 22 career tackles in the NFL.