Updated

A mass personal injury lawsuit has been filed by a group of former NFL players against the league in Philadelphia federal court.

Hausfeld LLP, a firm representing 106 retired football players, filed a complaint that alleges the NFL has long been aware of the serious risks to football players from head impacts and chose to downplay the scientific evidence acknowledging these risks.

The plaintiffs, led by former NFL player Brent Boyd and Hall of Famers Lem Barney, Joe DeLamielleure and Paul Krause, contend the league caused serious injuries to thousands of players as a result of the NFL's improper conduct.

"As the NFL prepares for the Super Bowl, it has forgotten about the legacy of its former players, many of whom built the league and are now suffering from the devastating consequences of on-field head injuries," said Richard Lewis, a partner at Hausfeld LLP involved in the case. "The NFL needs to step up, do the right thing, and compensate the injured retirees who made the game what it is today."

The lawsuit, filed Monday, follows similar suits filed last month in federal courts in Miami, New York and Atlanta.