Chelsea had a verbal agreement for a five-year contract with Mendy, but have found it harder to come to an agreement over a fee for their primary goalkeeping target.
According to reports, Chelsea and Rennes have already agreed the terms for the 28 year-old player.
“Edouard Mendy will be in London on next few hours – the deal is 100% done”, tweeted Fabrizio Romano, a knowledgeable source on European football.
“The deal is done !! Ready for medicals and signing. #Chelsea have a new great goalkeeper. Good luck to #Mendy”, wrote Sky Sport journalist, Angelo Mangiante.
Mendy is expected to replace Kepa Arrizabalaga, as Chelsea’s first choice keeper.