Clinton Portis (shown in a 2008 game) is suing the NFL. (John Froschauer / AP)

Former Washington Redskins running back Clinton Portis is the lead plaintiff in the latest lawsuit to be filed against the NFL over concussions.

Portis and 81 other players, including Daunte Culpepper and Cadillac Williams, filed the suit in U.S. District Court for the Southern District of Florida, the Washington Times’ Nathan Fenno reports.

The league is facing dozens of lawsuits involving around 4,500 former players who claim they are suffering long-term effects from brain injuries sustained during their playing days and that the NFL concealed the danger of concussions. Portis, who retired last August, estimated that he had 10 concussions during his nine years with the Denver Broncos and Washington. Former Redskins Art Monk and Mark Rypien have also joined lawsuits against the league.

Earlier this summer, a Pennsylvania judge ordered the NFL and attorneys for more than 4,000 former players to mediation.

Follow @CindyBoren on Twitter and on Facebook.