Raphael Varane is set to be out of action for a month and has been ruled out of the Manchester derby this weekend after picking up a hamstring injury in the Champions League on Tuesday.

The Frenchman was forced off in the first half of Manchester United’s 2-2 draw with Atalanta in Bergamo on Tuesday and assessments have revealed he will not be fit for this weekend’s crunch clash with Manchester City.

The news will come as a blow to Ole Gunnar Solskjaer, who has only just got the centre back back for selection after he recovered from a thigh problem.

Club sources confirmed on Wednesday evening that after an assessment with the club’s doctors, Varane is expected to be out for up to a month with a hamstring injury.

That immediately rules him out of the Manchester derby this weekend and also means he is unlikely to be available for the games against Watford, Villarreal and Chelsea after the international break.

It is hoped Varane will return for the start of December, however, any problems with his recovery could also make him a doubt for the Premier League home game against Arsenal, and United’s final Champions League group stage game against Young Boys.

After the game, Solskjaer said he was not optimistic but needed to wait for further medical assessment to offer clarity on the issue.

“He felt his hamstring. So, of course, you can’t take any risks, unfortunately,” Solskjaer told BT Sport. “Rafa has been such a calming influence when he’s on the pitch. We lost him but that’s football.”