Chelsea boss Thomas Tuchel has confirmed that left-back Ben Chilwell has suffered a partial tear of his ACL, although no decision has been made on whether he will need surgery.
Chilwell went down with 20 minutes to go in Chelsea's 4-0 win over Juventus on Tuesday after jarring his knee, with reports soon suggesting that his season could be over.
Speaking ahead of Sunday's visit of Manchester United, Tuchel confirmed that Chilwell had avoided a full tear, but he is still facing a substantial period on the sidelines while club doctors determine whether surgery will be necessary.
"He has a partial tear of his ACL, and the decision is to treat it conservatively," Tuchel told a press conference. "The next six weeks will tell the story if he makes it and be available or if he will need surgery.
"There is never a good moment for big injuries or injuries in general. This personally is a very bad moment because he was so involved and full of confidence. He was so important in our victories.
"We are very sad but he at the moment is very positive because his body has reacted positively to the first treatments and the injury."
With Chilwell sidelined, Tuchel is expected to turn to Marcos Alonso for the majority of the minutes at left wing-back, while there have even been shouts for both Saul Niguez and Callum Hudson-Odoi to feature while Chilwell recovers.
There has even been speculation that 19-year-old Ian Maatsen, who has been impressing out on loan with Coventry City, could be recalled once the January transfer window opens.
Elsewhere, Tuchel confirmed that Mateo Kovacic remains sidelined, while fellow midfielder N'Golo Kante will almost certainly miss out after tweaking his knee against Juventus.
Striker Romelu Lukaku will be back in the squad, but Tuchel was keen to avoid raising expectations for the Belgian as he prepares to return from an ankle injury.
He said: "The possibility [Lukaku] starts is not very high because we can't be sure what happens in the match and we have to find the balance to giving minutes and being absolutely competitive for 90 minutes."