Manchester United will be without Alexis Sanchez for four to six weeks after he suffered a "bad" knee injury, caretaker boss Ole Gunnar Solskjaer has confirmed.
Speaking ahead of that second leg in Paris, Solskjaer said: “He might be out for, it was a bad knee injury, so if it is four weeks or six weeks. Hopefully, he will recover quickly.”
After losing the first leg 2-0 at Old Trafford, Solskjaer has named five youngsters in his squad for the return game at Parc des Princes and left out Jesse Lingard and France international Anthony Martial.
Teenagers Tahith Chong, Mason Greenwood, Brandon Williams, Angel Gomes and James Garner have all travelled to France.
“I think every young player at this club is dreaming of having the impact Rashy’s [Marcus Rashford] had," Solskjaer continued. "Tomorrow night might be a chance for some of the young ones.
“Brandon, full-back, can play both sides. It is the first time he has travelled with us, he didn’t expect to come.”
Striker Rashford burst on to the scene in 2016 at the age of 18 when Louis van Gaal was in the Red Devils' hotseat.
He scored five Premier League goals in 11 appearances that campaign and earned himself a spot in the England squad for the 2016 European Championships.
If United fail to gain a footing in the away leg and overturn the two-goal deficit, Solskjaer could be likely to give some game time to the youngsters.
The first leg remains the only game Solskjaer has lost since taking over in December, having led a considerable turnaround in the Reds' form.
Should he steer United to a quarter-final spot, Solskjaer's chances of being offered the permanent job this summer could increase dramatically given the disappointing performance at Old Trafford.