The 19-year-old midfielder has been one of the handful of players in at Cobham this week, with others away on international duty or already injured. He was supposedly getting closer to reaching full fitness after missing out on a preseason, but now that's going to take a bit longer.
Romeo Lavia unveiled as a Chelsea player. Source: Getty
Romeo Lavia has had a scan on his ankle over the injury, and Chelsea are now awaiting the results.
It is another blow for manager Mauricio Pochettino, who has endured a string of injuries to players since his appointment at the beginning of the summer.
Summer signing Christopher Nkunku is yet to make his competitive debut for the club after suffering a knee injury in pre-season against Borussia Dortmund.
Defender Wesley Fofana, midfielder Carney Chukwuemeka and striker Armando Broja have all suffered similar fates and are currently on the sidelines.
Chelsea's coach. Mauricio Pochettino. Source: Getty
The Blues' are slumped in 12th place on the table after their opening four games of the season.
With no European football at their disposal and huge sums splashed in the transfer window, much is expected of Pochettino's side this time around.
But a return of one win, two defeats, and a draw has raised more questions than answers so far. Chelsea will return to Premier League action with a trip to Bournemouth after the international break.