The wantaway defender was nowhere to be seen as his club prepared for the new Ligue 1 season, with speculation rising about his future at Stade Metropole
The 26-year-old was due back in training on Saturday after being granted an extended summer break following his exploits with France at Euro 2012.
However, the Fretin-born defender missed the session, and is expected back at the club early Monday morning.
Debuchy impressed as les Bleus reached the quarter-finals of the European Championship, and appears close to a move to the Magpies, although les Dogues director Frederic Paquet has stated that he will not be going anywhere until a replacement is found.
He helped Lille to a third-place finish in Ligue 1 last season, and was named in the National Union of Professional Football Players' team of the year.