According to Goal.com, Oxlade-Chamberlain's injury will see him sidelined for the next two weeks, which will see him also miss a crucial midweek clash against Schalke in the Champions League.
Oxlade-Chamberlain suffered a hip injury two weeks ago during Arsenal's 1-0 away defeat of Norwich, but was expected to return for the clash with United. According to Eurosport, a fitness test was all that stood in the way of the recently capped England international making a starting appearance for the Gunners.
Despite a hat-trick performance in Arsenal's exhilarating 12-goal thriller midweek against Reading, Theo Walcott is unlikely to receive a starting birth.
Wenger's choice to overlook Walcott is expected to fuel rumors that suggest the winger will leave Arsenal during the next transfer window. When asked about Walcott's future at the Emirates, however, Wenger said:
"There is urgency (regarding Theo Walcott's contract). We want to sort it out before Christmas, one way or the other. I always said it is important that he plays in the right position and that certainly would be through the middle in the future."
Arsenal lie in sixth position in the league, six points behind United.
A win at Old Trafford will lift the Londoners back into the top four, albeit temporarily.