Duo causing concern for Oxford Oxford could be without striker Jon-Paul Pittman and midfielder Adam Chapman for Saturday's clash with Bradford. Pittman was taken off 13 minutes into United's defeat to Cheltenham with a hamstring injury, while Chapman took a knock to his foot in the same game. The two players may join the club's long-term absentees while midfielder Jake Forster-Caskey is a doubt through illness. Luke O'Brien, 24, is vying for a place in the starting XI as Oxford boss Chris Wilder looks to shore up a defence that has leaked 13 goals in four matches. Defenders Lee Cox and Peter Leven returned to action on Tuesday after a spell on the sidelines and are both available for selection once again. Bradford goalkeeper Jon McLaughlin is doubtful for the game due to a hip injury. McLaughlin was forced out of the action in the closing stages of Bradford's midweek home win over Morecambe and replaced by Matt Duke, who could return to the starting line-up. Striker Nahki Wells, plus midfielders Garry Thompson and Ricky Ravenhill are all pushing for recalls. Wells, struggling with a hip problem in recent weeks, was impressive as a second-half substitute on Tuesday night, while Thompson missed out against his former club and has started only one league game since arriving from Scunthorpe in the summer. Ravenhill has yet to appear this season due to a knee injury. Midfielder Ritchie Jones is several weeks away from a return following knee damage, but manager Phil Parkinson has no other new injury or suspension worries as City chase a third straight league win.