Miller, who stopped 45 shots during a 1-0 loss Friday night against Ottawa, is day to day because of a lower-body injury. He is expected to return for the Sabres' home game Tuesday night against Tampa Bay.
Backup Jhonas Enroth started Saturday night.
Defenseman Henrik Tallinder sustained an upper-body injury Friday and will miss about a week.
The Sabres recalled goalie Matt Hackett and defenseman Alexander Sulzer from Rochester of the AHL. Sulzer cleared waivers Monday after failing to make the team out of training camp and was sent to Rochester. Hackett allowed six goals for Rochester in an 8-1 loss to Grand Rapids on Friday night.