Rennes, reports Le 10 Sport, are chasing Slimani for the winter market.
Rennes hope to take the Slimani on-loan for the second-half of the season, though face competition from England.
Ranieri claimed in an interview in the Italian press that Leicester asked him to return after the sacking of Craig Shakespeare.
However, the Leicester Mercury reports if Ranieri had received such a call it had not come from City or anyone representing them. The Foxes went with Claude Puel, who debuted with victory over Everton on Sunday.