Bednar missed last weekend's hard-fought 3-1 triumph over Derby due to a groin strain and is highly unlikely to have recovered in time for the trip to Loftus Road.
However, fit-again striker Ishmael Miller and winger Giles Barnes are in contention to provide a major boost for Roberto Di Matteo, although they are unlikely to start.
Miller (ankle) has been out of action for a month while Barnes (Achilles) is yet to pull on an Albion shirt in a competitive fixture and last did so over 12 months ago for Derby.
Di Matteo has also been boosted by the news winger Chris Brunt has recovered from the calf strain that forced him to withdraw from Northern Ireland's squad, while the club's eight other internationals have all come back from duty in one piece.
On-loan midfielder Ben Watson returns to QPR having spent a spell in the capital earlier this season.
New loan signing Steven Reid goes straight into the matchday squad.