Oxford University’s Nomura Varsity Match preparations have been dealt a major blow with back-row forward John Carter ruling himself out due to a shoulder injury.

The former Sale Sharks and Northampton man, who is also Oxford’s team manager, has stepped aside so as to not upset the squad’s Twickenham preparations.

Carter, 29, has delivered some aggressive displays after being persuaded to return as a player by head coach Murray Henderson.

And it was hoped he would have shrugged off the shoulder injury he picked up against Sale in time to face Northampton Saints.

Henderson said: “Unfortunately John Carter’s determination to be available for Saints and then Varsity, has been hindered by the magnitude of his shoulder injury and its slow recovery.

“In his mind it is now in the best interest of the Blues that he withdraw his availability to allow the playing squad to dedicate the time it needs to concentrate on likely combinations.”

Henderson added: “After deciding to come out of retirement and be available for all the right reasons, JC has now been forced to withdraw.

“His leadership alone will be a huge loss, but even more importantly he does things you can’t coach.

“They are instinctive things that come from ‘heart and soul rugby’ that I would imagine he has played all his career.

“He was known for his warrior look in his heyday and the Dark Blues will most certainly miss this warrior in December.”