Sabres coach Lindy Ruff said Tuesday that Miller does not have a groin injury. Ruff won't decide on Miller's status until Wednesday morning.
Miller returned to practice on a limited basis Tuesday after missing Monday's workout. He was often stretching his legs during breaks.
"I thought he looked OK," Ruff said. "I thought he was also taking it a little bit easy, just to give it a try. I think he's just trying to find out exactly where he is at."
Ruff said Miller started feeling some pain toward the end of Buffalo's 4-3 overtime loss to Atlanta on Friday.
"I felt better than I anticipated," Miller said. "I was just trying to keep it simple. The main thing is that I want to stay on top of things and keep going with treatment. I want to play, but I want to be sure that I'm giving the guys the best chance."
Miller has mirrored the slow start for Buffalo, which has a 3-7-2 record. After backstopping the U.S. Olympic team to a silver medal in February, his 2.71 goals-against average is the fourth-highest among five goalies who have started 10 or more games.
Still, Miller's absence would create a huge void for a Sabres team that is tied with Florida and Edmonton for the second-fewest points in the NHL (eight). After winning its season opener, Buffalo is winless in nine of its last 11 games, including a 4-0 shutout loss at Dallas on Saturday in which backup Patrick Lalime played.
Lalime is 0-2-0 with a 4.03 GAA in two starts this season.
"We need to win," Miller said. "Everyone feels it. We're all disappointed with our start. We could have been a lot more organized and could have worked together a lot better as a group in many different situations."