Trent Williams' season effectively ended Thursday when the Washington Redskins placed him on the non-football injury list, and it doesn't sound like the veteran left tackle intends to suit up for the NFC East club ever again.

"I feel like everything has run its course," Williams told USA TODAY Sports' Mike Jones on Friday. "I mean, I do want to play football still and I'm not a free agent until after the 2020 season, so who knows. But the bridge has definitely been burned, and any efforts now, basically are, in my opinion, pretty much just CYA (cover your ass)."

Williams hasn't played this season after holding out of Washington's first eight games. He revealed last week his anger stems from a cancerous growth on his head that team doctors didn't take seriously when it began developing six years ago.

The 31-year-old returned to the Redskins after the NFL trade deadline but failed his physical due to discomfort with his helmet.

The Redskins have requested an independent review of their handling of the medical care given to Williams. However, while Williams wants the matter investigated, he believes the team is only concerned with absolving itself of blame.

"If I felt like they were genuine, I'd be all for it,” Williams said. "They're not doing it to find out what went wrong. They're doing it to cover their butts.

"Mine isn't the only situation they got wrong. There are a lot of situations they could have looked into. Why didn't they do it before now? Why didn't they do it in (quarterback) Colt (McCoy's) case? And they keep putting out these false reports.

"That's never helpful. I just feel like regardless of what the findings of the investigation are, they're going to try to find a way to paint me negatively and make themselves look better."

The Redskins reportedly attempted to trade Williams hours before the deadline after months of insisting he wouldn't be moved but were unable to find a team willing to match their high asking price.

With Williams seemingly done with Washington, it's possible the team could shop him in the offseason.