Eric Bailly is set to be absent for Manchester United until after the next international window in November, Red Devils boss Ole Gunnar Solskjaer confirmed.
The Ivory Coast centre-back was on the bench when Manchester United defeated Newcastle United 4-1 at the weekend but did not travel for the impressive 2-1 win at Paris Saint-Germain in the Champions League on Tuesday.
Bailly has an unspecified muscular injury, which Solskjaer said will keep him out potentially for up to a month.
"Eric has a muscle injury, we think maybe three or four weeks, maybe after the international break he'll be back," Solskjaer said.
It presents a slight problem for the United boss, who was without Harry Maguire in the French capital, though he could be back against Chelsea this weekend.
Axel Tuanzebe excelled in a back three alongside Victor Lindelof and Luke Shaw in his first competitive appearance since December, meaning Aaron Wan-Bissaka and new signing Alex Telles were utilised as wing-backs.
