Huddersfield Town duo Joel Lynch and Martin Paterson will both undergo surgery on Monday.
Centre-back Lynch, who needs a minor operation on a thumb, will be able to continue playing, and is in the squad for tomorrow's Championship game at Wigan.
But striker Paterson, who has an unspecified arm injury, will not be considered for the DW Stadium visit and will take longer to recover.
Paterson and midfielder Adam Clayton were both left our of the squad for last week's 3-2 home derby win over Leeds amid talk of a training-ground bust-up.
Clayton and centre-back Anthony Gerrard, who was also omitted from the Leeds squad, both played for the Under 21s this week, but there was no sign of Paterson.
Manager Mark Robins refused to be drawn on his selection plans for Wigan, but hinted at a similar squad to last Saturday.
"The lads who played against Leeds did themselves no harm whatsoever," he said.