Rennes attempted to have Chelsea include Olivier Giroud in their offer for Edouard Mendy.
The Senegal goalkeeper is set to become the seventh signing in an extraordinary summer of spending for Chelsea after they had agreed a £25million fee with the Ligue 1 side.
L'Equipe says the Ligue 1 side had demanded a £37m (€40m) fee for Mendy along with the option of signing 33-year-old Giroud on loan for no charge at all.
However, that appears to have been rejected by the Blues who have now come to an agreement with their French counterparts on a £25m fee for the 28-year-old goalkeeper, whose contract at Rennes ran until 2023.
Mendy was left out of Rennes' 4-2 victory against Nimes on Sunday and now looks set to provide immediate competition for under-fire Kepa Arrizabalaga and Willy Caballero.