London - Paul Pogba could be out of action for a "few weeks" after suffering a suspected hamstring injury that took the shine off Manchester United's successful return to the Champions League, manager Jose Mourinho said.
United, who missed out on qualification for Europe's premier club competition last season, coasted to a 3-0 victory on Tuesday, with goals for Marouane Fellaini, Romelu Lukaku and Marcus Rashford.
Making his debut as United captain, Pogba lasted just 18 minutes of the Champions League Group A game before being forced off by an apparent left hamstring injury - with Fellaini taking his place.
The 24-year-old Frenchman reportedly left Old Trafford on crutches.
"I don't know (what the severity is)," Mourinho told MUTV, the club's in-house television station.
"I just know from experience it's a muscular injury. In my experience, muscular injury stops you from playing for a few weeks, I think.
"It looks for me too (like a hamstring injury) but I haven't spoken yet to the medical department."
But the United boss said he had midfield options for the weekend's Premier League clash with Everton, including Ander Herrera, Michael Carrick, Fellaini and Nemanja Matic.
France will be hoping Pogba is fit in time to play in the crucial World Cup qualifier against Bulgaria on October 7.