Jahvid Best, whose career as a running back with the Detroit Lions was cut short by concussions, is suing the NFL, according to a filing today in Wayne County Circuit Court.

Best, a first-round draft pick in 2010, suffered three concussions while with the Lions, after having two during his college career at Cal. He has not played since suffering his last concussion in October 2011.

His lawsuit argues that the NFL knew about the risks of head injuries suffered by players but didn’t do enough to protect them. The lawsuit also names helmet manufacturer Riddell as a defendant and seeks unspecified “economic and noneconomic” damages.