Chelsea head coach Liam Rosenior has revealed that Dario Essugo is set for another spell on the sidelines.
Although he made substitute appearances during the Club World Cup, the midfielder is still waiting to make his first outing of 2025-26.
Thigh surgery in September kept him out of training until the back of November before he suffered another setback in his bid to make his competitive debut in English football.
The 20-year-old has spent games on the substitutes' bench since Rosenior's arrival at the start of the month, only to be a surprise absentee from the group for Wednesday's Champions League fixture against Pafos.
Speaking to reporters at a press conference on Friday, Rosenior revealed that the Portugal Under-21 international faced a further period on the sidelines.
Rosenior provides Essugo, Jorgensen injury update
He said: "Unfortunately Dario picked up a really unfortunate injury. He slipped in training and he's going to be out for a while, over a month.
"It is a real shame because he's an outstanding player as well that I was really looking forward to working with."
Meanwhile, Rosenior is hopeful that goalkeeper Filip Jorgensen will be in a position to return to the squad next week, despite the issue that forced him off at half time versus Pafos.
Earlier in the media briefing, Rosenior said: "[Filip] Jorgensen had his scan, which is actually quite positive and not as bad as we first feared.
"He won't be available for Palace but could be potentially for Napoli."
Essugo blow to impact on transfer plans
Given his lack of game time, Essugo was a clear option to go out on loan before the end of the winter transfer window.
If Kendry Paez is recalled from Strasbourg, moving to France was a possibility, but the 20-year-old is now likely to stay at Chelsea.
Therefore, other fringe members of the squad could be considered for a temporary switch away from West London.