Chelsea striker Armando Broja will miss the rest of the season after rupturing his anterior cruciate ligament, the club have confirmed.
Broja, 21, collided with Aston Villa defender Ezri Konsa in a mid-season friendly in Abu Dhabi on Sunday.
“The scan results unfortunately confirmed a ruptured anterior cruciate ligament and that surgery will be required,” the club said.
“He will work closely with the club’s medical service during his rehabilitation.”
The Albania international thanked everyone for their messages of support and added social media: “It has been difficult to process everything these last few days, but I am determined to come back even stronger and better than before.”
Broja has made 12 Premier League appearances for Chelsea this season, including 10 as a substitute, and has scored once after a success. loan period at Southampton last season.
Chelsea, who have lost three games in a row before the World Cup break, will face Bournemouth at home on December 27.
They sit eighth in the Premier League table, 16 points behind leaders Arsenal.
Alistair Magowan, BBC Sport
Armando Broja’s injury will be a hammer blow for a striker who has yet to fully establish himself at Chelsea, and continues the club’s longstanding problems in attack.
The 21-year-old is highly regarded at Stamford Bridge, having signed a new six-year contract at the club last summer.
But he only scored his first Chelsea goal in October and missing the rest of the season could mean he will fall down the pecking order when he finally returns.
Chelsea were already short of strikers. Romelu Lukaku is on loan at Inter Milan for the rest of the campaign, meaning Pierre Emerick-Aubameyang is now their only fully fit marksman. This should trigger another move for the club into the transfer market in January.
Acting chairman and sporting director Todd Boehly has already made a move for RB Leipzig’s Christian Nkunku, but any deal is expected to come this summer. Chelsea now need a stopgap option and the allure of Cristiano Ronaldo may be tempting for Boehly.
It remains to be seen whether it is also tempting for the manager. Last summer, Thomas Tuchel said no to a deal for Ronaldo. Will Graham Potter think the same? Or will the Englishman think he has enough cover, especially as previously underdog wingers Christian Pulisic and Hakim Ziyech performed well at the World Cup?