Ryan told reporters during Friday's news conference that he contemplated between questionable and doubtful for the veteran back before opting for the slightly more optimistic of the two. The New York Daily News reported Friday that it does not appear likely that Tomlinson will play.
"If you're on a scale he's sliding into that one (doubtful)," Ryan said of Tomlinson's status. "He wants to go as badly as it gets. I want to make sure that he has protection from himself. I'm not going to force the issue, that's for sure."
Ryan added, "If I was a betting man, if we had to play tomorrow, I don't think he plays."
Tomlinson sprained his medial collateral ligament during the Jets' Week 10 loss to the Patriots and then sat out last week's loss to the Denver Broncos. He figured he'd be able to play against the Bills until experiencing soreness Tuesday after working out Monday.
"It's never fun to have injuries," Tomlinson said, adding that his knee is "100 percent better" than it was earlier in the week. "It's one of those things where we always feel like we can play, even though we're injured. Sometimes it hurts us to go out there and play injured, but that's what we do. And when you can't play, it does make you down. That's kind of where I am right now."
For a complete look at all injuries around the league, go to NFL.com's injury page.
The Associated Press contributed to this report.