Chelsea fear Romeo Lavia will miss at least six weeks due to the ankle injury he suffered in training last week.
Lavia went over on his ankle during a session on Thursday and had a scan the following day.
Early indications following tests are that Lavia has suffered some ligament damage and a problem serious enough to spark concerns he will be sidelined for at least a month and a half.
Chelsea have yet to confirm the full severity of the teenage midfielder’s setback with the situation expected to become clearer in the coming days.
Such a spell on the sidelines would further delay Lavia’s Chelsea debut until the end of October.
The 19 year-old has yet to make his bow following his £58m move from Southampton and instead been working to build up his fitness since his switch.
Chelsea have five games before the next international break in early October against Bournemouth, Aston Villa, Fulham and Burnley in the Premier League and Brighton in the Carabao Cup.
They return to action after the international break on October 21 against Arsenal and also host Brentford a week later.
