Colin Murdock who was forced to leave the field in last week's defeat at Cheltenham after just 2 minutes is definitely out of Saturday's game at Swansea.
The Millers captain broke down with a thigh strain and was replaced by Scott Wiseman.
Also out is Midfielder Michael Keane who is struggling with an Hamstring injury.
Meanwhile Centre-Half Pablo Mills who missed his first game of the season at Cheltenham is hoping to shake off a calf strain.
Gary Monk, who's own goal paved the way for the Millers excellent 2 -0 victory at The Liberty Stadium last season is out with a cruciate knee ligament injury.
Rotherham manager Alan Knill is looking to last years heroics at Swansea for a confidence booster, he said 'Swansea are coming off a big win against Carlisle but we went there in similar circumstances last season and won'.