The Algerian moved to the Foxes last summer from Sporting Lisbon for a club record £29million.
However, since making the switch, the 29-year-old has struggled to replicate his form from Portugal and he is struggling for goals.
It has led to rumours Slimani may leave in January and, according to L'Expression, Crystal Palace and Rennes are interested in him.
Both clubs are said to be tracking the striker in the hope Leicester decide to cash in on him now.
Slimani was linked with a move in the summer, but in the Foxes opted to keep hold of their man.