ORCHARD PARK, N.Y. -- A week after saying that he was "110 percent confident" that quarterback EJ Manuel would play Sunday against the New England Patriots, coach Doug Marrone was less certain about Manuel's status Monday.

Marrone said the Bills would "take a peek" at Manuel during Tuesday's practice, but made no guarantee that Manuel would play Sunday. Last Wednesday, Manuel was limited by a sprained left knee and sat out a win against the Miami Dolphins.

With one game remaining in their season, the Bills might ultimately choose to sit their rookie quarterback in the finale.

"I think there’s always a chance," Marrone said. "I mean, there’s a chance that Marquise Goodwin can’t play, there’s a chance that Aaron Williams can’t play. There’s a chance that someone can come in here tomorrow and say ‘I don’t feel well.’ So I think it’s very difficult."

So then why did Marrone declare so emphatically last week that Manuel would play? The first-year head coach said Monday that it's his job to be optimistic.

"You guys have known. You’ve been around me. I’m one of those guys, I really don’t know a lot about when it comes down to the specifics of injuries. I’ve been that way since training camp. But I’m always pushing, trying to get them out there and trying to get them to play," he said. "And I’m optimistic, probably more than everybody that’s here right now when it comes down to that. And I need to be. I really do. I need to be that way."