According to France Football, that news has alerted LOSC and OM who are looking at new strikers.
Their main priority for the attack is Gent forward Jonathan David, but Slimani is also on their list.
Slimani scored nine goals and contributed eleven assists in Ligue 1 for Monaco this season.
His Leicester contract ends in 2021 and the English club are hoping for a sum of around €8m.
The Foxes paid a club record fee of around €30m for Slimani but he scored only eight goals in one and a half seasons for them.