Williams was absent from minicamp and reportedly upset with the team's handling of a medical situation that involved removing a growth from his head. He's also reportedly seeking a new deal with two years remaining on his $68-million contract.
Williams has reached the Pro Bowl every year since 2012. When healthy, he's considered one of the best players at his position.
As one of the senior members of the team, Williams' absence would leave a big hole in Washington's offensive line.