Oxford will be without Alfie Potter for their FA Cup clash with Gateshead after he was ruled out for up to eight weeks.
United's star man was stretchered off during last weekend's shock loss to Bristol Rovers and an MRI scan on Wednesday revealed ankle ligament damage but no break.
One player who will be able to feature is Ryan Williams after parent club Fulham gave Chris Wilder permission to name him in their matchday squad for the tie.
But the U's are now waiting to see if Shrewsbury will allow Asa Hall to feature against the Skrill Premier outfit.
Gateshead midfielder James Marwood is hoping to return from injury.
Marwood has missed the last two games due to an ankle injury and could have a late fitness test, but striker Richard Brodie remains sidelined with an ankle injury.
Manager Anth Smith will also be without winger Marcus Maddison due to illness and left-back Luke O'Brien, who misses the chance of facing his former club due to the knee injury which has kept him out since mid-September.
Gateshead have won their last three away games and have won five of their last six in the league.