Bristol Rovers duo James Tunnicliffe and Stewart Campbell picked up knocks at the weekend and will face late fitness tests.
Rovers will also be forced to make a change in goal as loanee Mikkel Andersen is on duty with the Denmark under-21 side.
MATCH FACTS
Head-to-head
• These clubs have met 41 times. Oxford United have won 14, Bristol Rovers 16, with 11 ending all square.
• They have never clashed in the League Cup before.
Have your say on the game
Oxford United
• Oxford United are making their first League Cup appearance in five years.
• It's seven years since they last qualified for the second round.
• This is Chris Wilder's first taste of League Cup football as a manager.
Bristol Rovers
• Bristol Rovers are aiming to qualify for the second round for the fourth time in seven years, and the second year in a row.
• Rovers have not lost to lower-division opposition in the League Cup since 1998.
• The west country club have lost their last four away ties in the League Cup.
Source: BBC Sport
Source: BBC Sport