Souare joined from Lille last month and has been cleared to play in the game at Selhurst Park but Eagles captain Mile Jedinak remains sidelined with an ankle injury.
Yaya Sanogo (hamstring) and James McArthur (thigh) are also struggling to be fit in time while Shola Ameobi is still regaining fitness and unlikely to feature.
Liverpool captain Steven Gerrard is likely to be missing from the squad to face Crystal Palace after reports emerged that he will be sidelined for two to three weeks with a hamstring problem.
With Lucas Leiva already out for at least a month with a thigh problem it means Jordan Henderson and Joe Allen are likely to be paired in central midfield.
Forward Raheem Sterling, who missed the midweek league win over Tottenham with a foot injury, has to be assessed while youngster Jordon Ibe is cup-tied.