Oxford are hoping an illness bug has cleared in time for the arrival of Peterborough.
Manager Karl Robinson revealed five players, including Lewis Bate and Cameron Brannagan, had been struck down ahead of the midweek defeat at Sutton, forcing a late change of plans.
They could both come back into contention if they are passed fit for action, but Djavan Anderson, Alex Gorrin and Steve Seddon are vulnerable.
Forward Sam Baldock has yet to feature this season but was an unused substitute last weekend and could come into contention.
Peterborough have doubts over striker Ricky-Jade Jones, who has been struggling with an ankle injury.
Jack Marriott could get the nod in attack, but a full league debut for Jack Taylor or Ephron Mason-Clark are also possible.
Kwame Poku is on the way back but Harvey Cartwright, Emmanuel Fernandez and Oliver Norburn are sidelined.
On-loan Newcastle defender Kell Watts was handed his first appearance for the club in midweek and will hope to remain in the squad.
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