Manchester City defender Aymeric Laporte is set to miss the rest of 2019 after undergoing surgery on his right knee, leaving the team short of centre-back cover for their Premier League title defence and the group stage of the Champions League.
Laporte had the operation in Barcelona on Tuesday after "damaging his cartilage and lateral meniscus" during the 4-0 win over Brighton in the Premier League on Saturday, City said.
City didn't give an exact timeframe for Laporte's absence, but the nature of the injury means he is unlikely to play again until the new year.
"A more detailed prognosis will be provided in due course," City said Wednesday.
A lengthy absence for Laporte, who was described by City manager Pep Guardiola last week as the "best left-sided central defender in Europe," is a major blow to the English champions, who released long-serving captain Vincent Kompany in the offseason and have another centre back, John Stones, currently out injured.
That leaves Argentina international Nicolas Otamendi, who was largely overlooked last season, as the main centre back available to City.
Fernandinho, a centre midfielder, filled in as a centre back off the bench against Brighton on Saturday. Guardiola has previously mentioned he could use the Brazil international in that position more often this season.
City are in second place in the Premier League with 10 points from a possible 12. Liverpool lead after winning all four of their games and are again expected to be City's biggest rival for the title.
The group stage of the Champions League begins this month and concludes in December.