Chelsea remain some way off of AC Milan’s £25 million valuation after their £15 million offer for the 29-year-old was rejected.
According to French outlet L’Equipe, Maignan is growing frustrated with the club and has offered them an ultimatum.
Maignan has reportedly told them that if they don’t accept an offer from Chelsea, he will leave as a free agent once his contract expires at the end of next season.
The Blues are still confident a deal can be done for the France international and are hoping it can be done in time for the FIFA Club World Cup.