Raphael Varane suffered a hamstring injury that forced him out of Manchester United's Champions League draw with Atalanta. The 28-year-old was replaced in the first half after he sat down on the pitch and asked for treatment.
Varane only returned from a groin injury at Tottenham on Saturday and he played in the middle of a back three in that victory in North London.
That was a role he reprised against Atalanta but he lasted only 38 minutes before being replaced by Mason Greenwood as Ole Gunnar Solskjaer switched to a back four.
United were already without Victor Lindelof, who picked up a minor knock in training on Monday, and they will now be sweating on the fitness of Varane ahead of the Manchester derby.
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