Peter Murphy and Tom Eckersley are vying for a place in the Accrington defence ahead of Oxford's trip to the Crown Ground in the second round of the FA Cup.
Rob Atkinson's recall from his loan spell with Stanley by parent club Fleetwood, despite the fact he is cup-tied for the Cod Army's clash with Aldershot, has created a vacancy in the back four and boss Leam Richardson is expected to select either Murphy or Eckersley to fill the void.
Danny Schofield was unavailable for the midweek defeat against parent club Rotherham and the on-loan midfielder cannot be selected once more, although fellow loanees Matt Whichelow, Piero Mingoia, Karl Sheppard and Jack Sampson have no such concerns.
Sheppard and Sampson are among the strikers who will have to contend with the return of James Beattie if the former England international can shake off the knock that ruled him out against the Millers.
Oxford look set to welcome defenders Damian Batt and Liam Davis back into their matchday squad.
Batt has been out of action with a groin injury sustained during October but has returned to full training, while Davis is fully fit and ready for action after a hamstring problem.
``They are both good players and will be in our plans for Accrington,'' manager Chris Wilder told United's official website.
``We are starting to get big players back in the squad and playing games and that will kick us on.
``Tommy Craddock is not far behind them and Michael Duberry is only a couple of weeks away now so things look positive on that front.''
Oxford have never been beaten by Accrington in the five meetings between the sides and Wilder's side ran out 5-0 winners when they last met back in October.