The 25-year-old is out of contract at Marseille in the summer and has so far failed to pen an extension – and he could be set to walk away as a free agent.
Chelsea boss Jose Mourinho is reportedly lining up a January move for the centre-back as he bids to reinforce his struggling defensive unit in the New Year.
Meanwhile, Liverpool are long-term admirers of N’Koulou and the Merseyside club are keeping tabs on his contract situation in France.
But now they look set to face competition from Italy, with Lazio weighing up a move of their own, according to the Corriere dello Sport.
It has been suggested the Serie A side reckon Marseille could be open to a January approach to avoid losing him for nothing next summer.