Chelsea suffered a major injury blow after Reece James sustained a fresh hamstring injury.
Liam Rosenior confirmed in a press conference on Monday that the club captain had suffered the problem during the 1-0 defeat by Newcastle on Saturday.
"With Reece, he felt something in his hamstring at the end of the game against Newcastle,” Rosenior said.
“Really disappointing. We don’t know the full extent but it rules him out for tomorrow's game.
“It could be [weeks]. With a hamstring injury, it is never great. Hopefully we can get him scanned, know the full extent, and go from there."
Suggestions that James could be out for several weeks comes as a bitter blow to Chelsea, who face a tough run-in as they bid to finish the Premier League season in one of the Champions League places.
James has been impacted by injuries throughout his career but had previously steered clear of fitness issues during this campaign.
But he was not part of the first-team training session at Cobham on Monday morning and is set to sit out of action for an extended period.,
It means the 26-year-old is ruled out of Tuesday’s Champions League last-16 second leg against Paris Saint-Germain — with Chelsea trailing 5-2 in the tie — and is a major doubt for England’s friendlies against Uruguay and Japan later this month.
Rosenior also confirmed that James’ fellow right-back Malo Gusto was ill, but there was a boost for the Blues after Estevao returned to training.
“Malo is ill,” the Blues boss continued.
“We’ll have a look at him for tomorrow. Estevao is back in training. We’ll assess whether he can play a part in the game at some point."
Rosenior gave an update on Filip Jorgensen, who had been selected ahead of Robert Sanchez in Paris last week.
The Dane missed the Newcastle defeat after failing a late fitness test.
“With Filip, he has felt something in his groin and we will get it scanned,” Rosenior said of his goalkeeper.
