Damien Batt will miss Oxford's trip to Gillingham through suspension.
The 26-year-old received a straight red card 66 minutes into Tuesday evening's 2-1 defeat at Southend for a hefty challenge on midfielder Anthony Grant.
Batt will therefore miss the Gills clash as he starts a three-game ban, meaning Ben Purkiss is likely to replace him at right-back.
Purkiss has impressed since joining from York in the summer and is likely to be given a starting berth at Priestfield.
Batt's ban is the only concern for manager Chris Wilder as there are no other fresh suspension or injury worries.
The Us have lost their last two away games and will be keen to reverse that trend as they seek to climb into the play-off places.