Amsterdam police spokesman Frans Zuiderhoek said that officers attended to an accident in the city at around 11pm after "a taxi-cab hit a lamp-post".
Despite the diagnosis, Mendy was able to keep his sense of humour on Twitter, saying he is "joining Injury FC on loan for a couple monthes". I think our task now is just to support him (Mendy) and just to be there if he needs something from us.
"I don't know, we will wait until Thursday, but I am pretty sure it will be longer than we would like, unfortunately".
The Manchester City full-back noted an uncanny likeness between the chap wheeling his to theatre and Stoke star Jese Rodriguez.
But now, after hearing that he has ruptured his anterior cruciate ligament, he's maintained his playful online persona and made fun of his strife.
The prospect of losing Mendy for the rest of the season severely weakens Guardiola's strategy, as the France worldwide was a key part of his summer squad rebuilding.
Mendy became the world's most expensive defender in the summer after joining City from Monaco for £52m. City's midweek match against Shakhtar Donetsk saw Fabian Delph fill in Mendy's position, and the only other suitable option ahead of the club's weekend encounter with Chelsea comes in the form of natural right back Danilo.
City released left back Gael Clichy in the summer while Aleksandar Kolarov asked to leave to join Roma.