20-year-old Gnagnon only made his debut in the French top flight in January 2016, but became a key man for the Red and Blacks over the last 18 months.

The youngster made 27 appearances in Ligue 1 last term, and has the potential to form an excellent young African defensive partnership with Ramy Bensebaini in the heart of the Breton club's defence.

According to La Provence, OM are taken by his performances in the top flight, and are monitoring the progress of the centre-back.

The French source report that new OM coach Rudi Garcia has already contacted Rennes regarding a potential move.

They're likely to face a battle from Rennes, who will be unwilling to part too readily with the defender, who still has two years left on his contract at Roazhon Park.

After initially insisting that he hadn't decided to represent the Ivorian national side in May, the former France U-20 international ultimately did commit his future to the Elephants, becoming one of several bright talents to join Marc Wilmots' refreshed West Africans' squad.