"The fact that he is in such a groove right now, we have to look at it as the week goes on," Ryan told reporters Monday morning.
"Number one, I want to win this game. I think it's important to win this game," Ryan said. "If we can get to 11 wins, I think it's only been done five times in the history of the franchise. That would be huge. You want to go in (to the playoffs) with a win.
"Now, obviously, his health is the number one concern. It's kind of a fine line because he is hot right now," Ryan said. "We can't afford for him to take a dip. We need him to stay at this level. ... I don't want to say 100 percent he's out or he's in, to be honest with you. That's what I'm weighing right now."
Sanchez seemed fine in the Jets' 38-34 loss to the Chicago Bears on Sunday, after playing during most of last week's win over the Pittsburgh Steelers with a shoulder injury. The second-year starter threw for 269 yards and a touchdown, completing 24 of 37 passes, as the Jets (10-5) clinched their second straight postseason trip under Ryan thanks to Jacksonville's 20-17 loss to the Washington Redskins.
Ryan talked Monday about the possibility of starting Sanchez against the Bills and pulling him early for backup Mark Brunell. Ryan said he hasn't made a final decision on how much playing time either quarterback will receive.
"That certainly will be discussed, for sure. I don't want to say. I'm really not clear right now," Ryan said.
The Associated Press contributed to this report.