Chelsea manager Frank Lampard is keen on signing a goalkeeper this summer after losing faith in Kepa Arrizabalaga.
According to Daily Mail, Chelsea have asked about Rennes goalkeeper Edouard Mendy and could offer Chelsea defender Fikayo Tomori in a swap deal.
The Senegal international, 28, has long been admired by Chelsea head of goalkeeping Christophe Lollichon who had a previous spell at Rennes himself.
Rennes have enquired about signing Tomori on loan this summer and could request the defender be included in any deal for Mendy.
Meanwhile, Chelsea boss Frank Lampard wants to appoint Anthony Barry from Wigan Athletic as his assistant alongside Jody Morris.