The game represents the last realistic chance for Gary Brazil and the Reds to stake a claim for the play-offs with the gap to the top six now four points with five matches remaining.
Their opponents, strongly fancied to win the division at the beginning of the campaign, saw their hopes of automatic promotion ended in midweek with defeat at Blackburn and indifferent results on the road have been a problem all season. The R's Boxing Day trip to the City Ground ended in a 2-0 win for the hosts thanks to goals from Greg Halford and Andy Reid.
Harry Redknapp's side, however, have been strong in their West London base all season with just two defeats from twenty home matches to date.