In the days before the Super Bowl in 2015, Marshawn Lynch taunted the media — and the N.F.L., which requires all players to speak to reporters before the championship game — by proclaiming, “I’m just here so I don’t get fined.”

It was peak Lynch: Defiant, funny, original. He got away with it, too, because he was a superb running back, a cornerstone of the Seattle Seahawks teams that made it to the Super Bowl in consecutive years.

Now Lynch is back in Seattle after an uneasy departure following the 2015 season. Not to avoid getting fined, but to save the team’s precarious playoff chances.

Lynch, according to his agent, signed a contract with the Seahawks, who have lost several of their top running backs to injury in the past several weeks, including Chris Carson and C.J. Prosise in a loss on Sunday to the Arizona Cardinals.