McArthur, who came off the bench for the final fifteen minutes against the Foxes, comes in from the start in place of Jairo Riedewald in midfield, while Ward replaces Nathaniel Clyne in defence.
Elsewhere, Scott Dann returns to the matchday squad.
For the visitors, Chris Wilder makes three changes from the side that lost at Burnley: George Baldock and Rhian Brewster drop to the bench while Jack Robinson is not in the squad; John Fleck, Oliver Norwood and Jayden Bogle come into the lineup.
Palace: Guaita (GK), Ward, Tomkins, Kouyate, Mitchell, Schlupp, Milivojevic, McArthur, Townsend, Zaha, Benteke.
Subs: Butland (GK), van Aanholt, Dann, Ayew, Sakho, McCarthy, Batshuayi, Eze, Riedewald.
Sheffield United: Ramsdale (GK), Stevens, Fleck, Basham, Mousset, Egan, Norwood, McGoldrick, Bogle, Ampadu, Osborn.
Subs: Verrips (GK), Baldock, Lowe, Brewster, Bryan, Hackford.