Lewis was wearing a walking boot on his right foot after an overtime loss to the Cincinnati Bengals on Sunday. Coach Doug Marrone said Monday that X-rays and an MRI on Lewis' foot were clean and that he "feels good" about Lewis' chances to play in Week 7 against the Miami Dolphins.
Flynn said the Bills contacted him last week after he was released by the Oakland Raiders.
"We were talking about bringing him in for a workout prior to the game," Marrone said. "What we're doing is trying to make sure that we have enough players on our roster, with the amount of injuries we've had, so that we're backed up with people who can go out there and be able to do it."
Prior to his release, Flynn was demoted to third on the Raiders' depth chart.
In his one start this season, a Sept. 29 loss to the Washington Redskins, Flynn went 21-of-32 passing for 227 yards and a touchdown but threw an interception and was sacked seven times.
"I'm happy I'm getting a fresh start," Flynn said Monday. "One game isn't going to affect my overall confidence or my belief in what I can do."
Marrone said as long as Lewis is ready to play Sunday, either Flynn or undrafted rookie Jeff Tuel will serve as the backup against the Dolphins. The Bills remain reluctant to play Tuel, who approached Marrone about his status Monday.
"I told him that it hasn't really changed, we see you as a young quarterback that's developing," Marrone said. "Do I expect you to be happy with [the decision]? No. I don't want you to be. ... I told him that if you're upset with it, that's fine. You don't have to agree with it. You have to do it, but you're the one that can change it by getting better."
"The report today was encouraging," Marrone said. "When you say 'ahead of schedule,' people ask about a timeline. I'm waiting for the doctor to give me a timeline."