Dianna Marie Russini of ESPN reported Knighton told the team he has chosen New England but hasn't signed the contract yet.
Without a caption, Knighton posted a photo of himself wearing a Patriots uniform:
Earlier on Thursday, Ben Volin of the Boston Globe reported there was "strong interest" between Knighton and the Patriots, and he was going to choose between the Patriots and Washington Redskins.
Knighton recorded 29 tackles and 1.5 sacks in 2015, his lone season in Washington. He spent the previous two years with the Denver Broncos, emerging as a vital run-stopping fixture. The Temple product was again stellar during his short stint in Washington, making him wonder why so many teams were giving up on him.
"I'm not really understanding why a guy like me, and what I bring to a team and what I bring to the field, is bouncing around like this," Knighton said, in an appearance on SiriusXM Radio, per Jared Dubin of CBS Sports. "But it'll catch up with itself."
It remains possible that Knighton finds himself back in Washington. The one-year, $4 million deal he signed with the team last season was a steal, and he's maintained he won't hold any personal grudges this time in free agency:
I haven't gotten any hint that they want me back or anything. To me personally. I haven't heard anything. And like I said, that's one thing I'm not going to stress about. Last time around I was hoping that something could get done with Denver and I was praying on that, I was talking it up all the time whenever I talked to the media because I felt in my heart that's where I was going to be. My emotions got caught into it. This time around, I understand it's a business.
That said, Pot Roast to the Patriots would be a classic move by Patriots head coach Bill Belichick. Knighton is being undervalued on the open market. He doesn't bring much in terms of pass-rushing efficiency, but his combination of bulk and speed off the line typically requires two offensive linemen to block. Having him in place makes everything easier for members of the front seven.
With New England still looking for a proper Vince Wilfork replacement, Knighton can be a short-term answer.
Follow Tyler Conway (@jtylerconway) on Twitter.