France full-back Mendy, 29, left City at the end of his contract this summer.He was cleared of a series of rape and attempted rape charges made against him.
It is alleged City stopped paying Mendy in September 2021 after he was initially charged and held in custody.
In a statement, it was confirmed leading UK sports lawyer Nick De Marco is handling Mendy’s case, which amounts to a “multi-million pound claim” and it is expected the case will be heard in 2024.
Mendy joined Ligue 1 club Lorient at the start of this season and he has so far made three substitute appearances for the French side.
He joined City from Monaco in a £52m deal in 2017 and won Premier League titles in 2018, 2019 and 2021.
His final appearance for the club came in the Premier League on 15 August 2021.
Mendy was remanded in custody for five months before being released on bail in January 2022, and then went to trial for the first time in August 2022.
In January he was cleared of six counts of rape and one count of sexual assault.He was then cleared of raping a woman and attempting to rape another in July at a retrial.
City did not comment when approached by BBC Sport.
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