The French fullback's season is likely over after tests revealed he tore the ACL in his right knee in a rout of Crystal Palace.
Manchester City have confirmed that fullback Benjamin Mendy has ruptured the anterior cruciate ligament in his right knee; likely meaning a lengthy spell on the sidelines for the French international.
The recent signing from Monaco picked up the injury in City's emphatic 5-0 win over Crystal Palace on Saturday, and having undergone tests with a specialist doctor in Barcelona on Thursday, it was confirmed that he would have to undergo surgery on his knee.
Manager Pep Guardiola was pessimistic about Mendy's situation in the aftermath of the weekend's victory, suggesting the France international could be unavailable for so long that City would have to pursue a replacement in the January transfer window.
The France international has made a promising start to life in the Premier League. He had already started four matches this season and City had won all of them, including three games in which they scored five or more and did not concede.
The club invested heavily in fullbacks during the transfer period, having allowed the Gael Clichy, Bacary Sagna and Aleksandar Kolarov to leave. They added Kyle Walker from English rivals Tottenham Hotspur and Danilo from Spanish heavyweights Real Madrid, as well as the capture of Mendy in order to add dynamism down the flanks.
But the news of Mendy's injury will come as a major disappointment to those concerned with the club and they have wished him a speedy recovery.