Etherington shook off a hamstring strain to play in Saturday's 3-0 FA Cup fifth-round win over Brighton, only to be taken off with a back injury understood to be linked to a defect in his jawline.
Asmir Begovic will return in goal ahead of Thomas Sorensen, who has so far played in all the FA Cup ties, while Dean Whitehead is also due to figure after being rested as a substitute for the game with Albion.
Manager Tony Pulis only has two players definitely out injured in Mamady Sidibe (Achilles) and Abdoulaye Faye (hamstring).
Source: PA
Source: PA