JOHN Mousinho’s knee operation means signing a centre back is Karl Robinson’s priority this month.

The Oxford United club captain is set to go under the knife next week to fix an issue that has dogged him since last February.

Surgery on his right knee will likely sideline the 34-year-old for nine months, during which time he will continue to gain coaching experience.

It leaves Elliott Moore and Rob Atkinson as the U’s only specialist first-team centre backs.

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The pair have formed a solid partnership during United’s current eight-match unbeaten run, giving head coach Robinson a dilemma as he seeks to add cover during the January transfer window.

“Centre back has become of the utmost importance,” he said.

“Do we try and buy somebody we can develop, which has been a philosophy of ours in that position, or do we try and find someone ready-made?

“The difficulty is that the two centre backs have been magnificent all season.

“Elliott Moore’s started to captain our club and, if you ask the fans, Rob Atkinson’s probably the most excited they’ve been about a centre back for a long time.

“It’s finding that one who wants to come to the club but knows his game-time can be quite limited over the next few weeks – unless one of the two centre backs gets an injury.”

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Mousinho’s absence means he is set to be left out of United’s registered squad for the second half of the season.

The U’s are allowed a maximum of 22 players aged over 21, with Joel Cooper’s loan return to Linfield freeing up another space.

Robinson revealed last month he wanted four signings during the window, with a replacement for the winger also high on his shopping list.

But while reinforcements out wide and at centre back are where his focus lies, United’s manager is confident several members of his squad can plug any gaps that appear.

Robinson feels Sam Long and Jamie Hanson can provide cover for Atkinson and Moore if needed, while Sean Clare and Jordan Obita are able to fill in at full-back and on the wing.

He said: “Even though we don’t have another specialist centre back, we still have players who can fit in that position.

“All the players who can play in a number of different positions have ticked a few boxes that we didn’t think we had available.”