Coach Lindy Ruff provided the update after practice Monday, saying he's pleased with the progress his starter showed.
Remaining cautious, Ruff ruled out Miller from playing at New Jersey on Wednesday, and calls it a "long shot" for him to play the following day at the New York Rangers. The Sabres (4-9-2) then host Washington on Saturday.
Last season's Vezina Trophy winner has missed four games since feeling the undisclosed muscle grow tight during a 4-3 overtime loss at Atlanta on Oct. 29. Miller says the weekend off helped, though he doesn't feel 100 percent yet.