Oxford boss Chris Wilder concedes his side's play-off hopes are all but over.
United slipped back off the pace following the 3-0 defeat by Bury on Saturday and are now five points behind seventh-placed Gillingham with six games left.
"Our season's effectively over," admitted Wilder.
"We've really shown that we are not good enough to get involved in the end-of-season activities."
Source: PA