Edouard Mendy is reportedly undergoing a medical at Chelsea ahead of completing a switch from Ligue 1 side Rennes.
The Blues are believed to have already agreed terms with the goalkeeper and his club on a deal worth up to £22m.
Sky Sports News claims that Mendy arrived in London on Monday to put the finishing touches to the transfer, which is expected to be announced on Tuesday.
Senegal international Mendy is expected to go straight into Chelsea's starting lineup following another calamitous display from Kepa Arrizabalaga in Sunday's defeat to Liverpool.
Frank Lampard is said to have previously targeted Mike Maignan, but Lille's £32m valuation put Chelsea off making a move.
Mendy kept nine clean sheets in 24 Ligue 1 appearances in 2019-20 and has featured once for Rennes so far this season.