Maxence Lacroix is set for weeks on the sidelines after tearing his left hamstring during Chelsea's EFL Cup defeat to Liverpool.
Lacroix was tracking a run from Cody Gakpo towards the end of the first half at Anfield when he suddenly pulled up and had to be withdrawn.
The centre-back will accompany Emiliano Martinez, Joao Pedro, Jamie Gittens, Reece James, Jorrel Hato and Pep Chavarria on the treatment table as injuries begin to pile up for Blues boss Xabi Alonso.
"Max picked up an injury and we expect that he will not be ready before the international break," Alonso explained. "So he will be a few weeks out."
Lacroix joined Chelsea from Crystal Palace during the summer transfer window for a fee of £52million.
The France international has been a mainstay in central defence for Chelsea this season having started in all but one of their Premier League fixtures since arriving at Stamford Bridge.
With Alonso to adjust in Lacroix's absence, we've assessed how many matches the Frenchman will miss.
Maxence Lacroix Injury Timeline: When will the Chelsea defender return?
The severity of Lacroix's hamstring injury means the defender will not feature in Zinedine Zidane's plans for the upcoming international break in November.
Chelsea have two fixtures before then: Manchester United at home and Sunderland away.
Alonso added Lacroix would be monitored over the coming weeks, and while they hope he will be available again after the international window, French publication RMC Sport revealed there is concern the 26-year-old could be out until 2027.
After the final international break of the calendar year, Chelsea face Leeds United (H) and Nottingham Forest (A) in November prior to a congested December period with three games in 10 days: Crystal Palace (H), Liverpool (H) and Manchester City (A).
The Blues host Aston Villa on the 21st December ahead of trips to promoted sides Coventry City and Ipswich Town on the 27th and 30th respectively. Chelsea then have matches against Newcastle United and Crystal Palace to start the new year before the FA Cup third round.
So if Lacroix's worst fears are realised, he could miss as many as 12 Premier League matches.
