JOHN Mousinho has been ruled out for at least a month – but there are concerns the Oxford United skipper could be sidelined for twice as long.

The defender sustained a knee problem late on in Saturday’s 1-0 defeat to Sunderland, which rules him out of tonight’s Sky Bet League One clash with AFC Wimbledon.

United were worried it would be a long-term problem, but a scan yesterday allayed those fears – although it will still mean a big chunk of what is left this season.

Boss Karl Robinson said: “John Mousinho twisted his knee on Saturday.

“The scan wasn’t what we thought, which is great news. We thought it was going to be a lot worse than it actually is.

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“It’s still going to be four weeks, minimum, but it could be eight.

“The reason for the difference is there’s so much inflammation that we’ve got to wait for it to settle down.

“He did it with 15 minutes to go, it’s amazing he stayed on.”

Mousinho has made 33 appearances this season, 29 of them from the start.

While Elliott Moore is a ready-made replacement at centre half, Mousinho’s absence will cause a headache if Rob Dickie picks up another booking.

The centre back will be suspended for two games if he is cautioned in the next seven matches, after which there is a cut-off.