The 19-year-old right-back is highly-rated with a number of clubs said to be chasing his signature this summer as he enters the final year of his contract with the French club.
Celtic are in the market for a right-sided defender after the sale of both Jeremie Frimpong and Hatem Abd Elhamed last season. Jonjoe Kenny was brought in on loan from Everton as cover but he has returned to his parent club.
Journalist Ekrem Konur reports that Ange Postecoglou’s side have made a £3 million bid for the player, while fellow writer Fabrizio Romano has also revealed the two clubs are in discussions over a transfer.
French publication L’Equipe are reporting the Ligue 1 side are demanding at least £4.3 million for Soppy and expect to drive up the price with other suitors poised to submit offers.