Edouard Mendy is having his medical at Chelsea after the club agreed a £22m fee with Rennes for the goalkeeper.
The deal is expected to be completed in the next 24 hours following his medical and finalising personal terms.
Pressure has increased on Frank Lampard to bring in a new goalkeeper following two mistakes from Kepa Arrizabalaga from their opening two Premier League matches.
Petr Cech, Chelsea’s technical director, has strong links with Rennes and has been involved in identifying Mendy as a target.
The 28-year-old kept nine clean sheets in 24 Ligue 1 appearances last season.
Mendy will become Lampard’s seventh first-team summer addition, joining Timo Werner, Hakim Ziyech, Ben Chilwell, Thiago Silva, Malang Sarr and Kai Kavertz.