Midfielder Elliot Lee will miss Oxford’s Sky Bet League One clash with Charlton on Saturday.
The on-loan Luton man is set to be absent for the game against the Addicks and the trip to Swindon three days later after being forced off in the first half of Tuesday’s 0-0 draw with Peterborough by a knee problem.
Striker Sam Winnall, having sat out that contest due to his ankle injury, was set for a scan on Thursday.
Sam Long was due to have one on Friday after suffering a hamstring issue against Posh, while a scan for James Henry (hamstring) on Tuesday saw him ruled out for four weeks.
Charlton forward Chuks Aneke is expected to be fit to feature at the Kassam Stadium.
Aneke scored the winner at Wigan in midweek before limping off late on.
Midfielder Darren Pratley will complete a two-match ban following his second dismissal of the campaign against Blackpool last weekend.
Ryan Inniss (quad) remains absent but is due to resume full training next week, while Alex Gilbey (hamstring) is also unavailable.