Williams, who is under contract through 2020, is not expected to attend the final two days of the minicamp. The NFL Network first reported Williams' desires for a new contract. Redskins coach Jay Gruden said the matter was between Williams, his agent, Redskins president Bruce Allen and senior vice president of football operations Eric Schaffer.
The Redskins weren't caught off-guard, as Gruden said they had been talking to Williams.
"It's personal between him and the agent and the organization," Gruden said. "We'll handle it accordingly. Trent knows we all want him back. I want him back in the worst way. His teammates want him back in the worst way. There is a business side to pro football, and that's what he's about right now so we'll find out what happens.
"Hopefully we will get it situated soon and get him back here."
Williams is still among the highest-paid tackles in the game, despite signing a five-year deal in 2015. His base salary of $11 million ranks fourth among tackles. His cap hit of $14.9 million ranks seventh.
But this offseason Trenton Brown received $36.25 million in guaranteed money from Oakland and has a $15.25 million cap hit. Last offseason, Nate Solder received $34.8 million in guaranteed money from the New York Giants while Taylor Lewan got $50 million guaranteed from Tennessee. They have cap hits of $17 million and $16.7 million, respectively.
Williams, 31, has made seven Pro Bowls and was a second-team All-Pro in 2015.
"He's the best left tackle in pro football," Gruden said. "He's a great player for us, a great leader. Love to have him here without a doubt. "
The Redskins are thin at tackle. Right tackle Morgan Moses returned from offseason ankle surgery, but he was involved in full-team work Tuesday. Backup Geron Christian continues to recover from MCL surgery. Veteran Ereck Flowers worked as the starting left tackle in Williams' absence.
Even if Williams had shown up to Ashburn, it's unlikely he would participate. Williams had a growth removed from his head and Gruden said he still would have been sidelined. Because of injuries -- or suspensions -- Williams has not played all 16 games since 2013. He has missed a combined nine games the past two years, but has been impacted by injuries throughout most of the last two seasons.
Running back Adrian Peterson, who trains with Williams in Houston, said he had a "pretty good idea" he wouldn't be here.
"I do know when he comes in here he'll be ready to roll," Peterson said. "His film speaks for itself."