The Irish centre-half this week went under the knife after aggravating his long-standing shoulder problem in training and is facing three months on the sidelines.
Claude Davis and Jose Fonte will therefore keep their places at the back.
Winger Sean Scannell is still doubtful with a hamstring problem and full-back Lee Hills is suspended so boss Neil Warnock could name the same side which beat Watford 3-0 last weekend.
Strikers Victor Moses and Alan Lee were on target and should retain their spots with Freddie Sears on the bench.
Darren Ambrose scored for the sixth successive game against the Hornets, a feat never before achieved by a Palace midfielder.
Doncaster goalkeeper Neil Sullivan is hoping to overcome a dead leg in time for the trip.
The former Chelsea and Leeds veteran was replaced by Ben Smith in last week's defeat at Nottingham Forest but could make the starting line-up.
Manager Sean O'Driscoll could be tempted to make changes to his defence after seeing his side let in four goals at the City Ground.
Skipper Martin Woods was recalled to the midfield last week but central defenders Adam Lockwood (foot) and Byron Webster (elbow) remained on the substitutes' bench after returning to the squad following long-term injury.
Doncaster, 18th in the table, have yet to win away from home in the Championship this season having drawn four and lost five.
Sporting Life