Southend could have Britt Assombalonga available for the visit of the U's.
The on-loan striker has not featured since Boxing Day, when he injured his ankle in the victory over Dagenham.
In the seven games he has been absent, the Shrimpers have won just twice - a penalty shoot-out win over Oxford in the Johnstone's Paint Trophy and a 1-0 win against Chesterfield in the league on Saturday.
Assombalonga will be assessed ahead of the game but is expected to be involved in the squad, while midfielder Ben Reeves could be handed a debut after arriving on loan from Southampton.
Marc Laird and Caolan Lavery are doubts as they battle back from injury.
Midfielder Laird has been sidelined with a hamstring problem while on-loan striker Lavery is struggling with a knock. Both will face fitness tests ahead of the game.
Oxford will be without veteran defender Michael Duberry.
The 37-year-old was taken off after just 21 minutes of the 1-1 draw with Burton with a hamstring injury and he confirmed on Twitter that he expects to be out for between two to three weeks.
He was replaced by Tuesday night by Michael Raynes and the centre-back could get the nod from the start at Roots Hall.
The club will also assess influential midfielder Peter Leven who was withdrawn at half-time after feeling unwell.
One player who will be available is striker Justin Richards after he missed the midweek draw as he is on loan from the Brewers.
His return gives Chris Wilder a striking headache after James Constable scored on his return from suspension alongside Tom Craddock.
Oxford sit just four points behind their weekend opponents, with the Shrimpers currently occupying the final play-off place in npower League Two.