Former Detroit Lions running back Jahvid Best is suing the NFL and helmet maker Riddell after concussion problems helped cut short his career.
Best was selected by the Lions in the first round of the 2010 draft and accounted for 1,000-plus yards and six touchdowns in his rookie season.
But he was limited to six games in 2011 after what he said was the third concussion of his football career. He was cut by Detroit last July.
The lawsuit was filed in Wayne County Circuit Court on Tuesday.
It alleges the league has been aware of evidence of mild traumatic brain injuries and the risk for its players for years, but "deliberately ignored and actively concealed" the information.
Messages were left seeking comment from the NFL and Riddell.