French Chelsea striker Christopher Nkunku has undergone knee surgery and will be sidelined for “an extended period”, the London club announced on Tuesday.

The 25-year-old player, who has already missed the World Cup in Qatar through injury, will therefore be absent for the start of the Chelsea season and very likely for the next matches of the France team, France-Ireland in qualifying for the Euro-2024 (September 7) and Germany-France (September 12).

Nkunku “has been operated on and will now begin a rehabilitation program with the club’s medical team”, explains the London club in its press release, without specifying the nature of his injury or the duration of his absence. According to British media, Nkunku could be out for four months.

After joining Chelsea in June from Leipzig for more than 60 million euros, he was injured last week in a friendly match against Dortmund (1-1) in Chicago. He had scored three goals in his first pre-season matches.

Chelsea begin their Premier League season on Sunday by hosting Liverpool.