The 27-year-old Lille full-back was due to travel to the north-east after the two clubs finally agreed a fee, understood to be in the region of £5 million, over the weekend.
However, with a medical to complete and personal terms to discuss, his transfer is unlikely to be concluded until later in the week.
Debuchy has been in Newcastle's sights for some time, and manager Alan Pardew was hugely disappointed to miss out on one of his major targets after the two clubs were unable to reach agreement over him despite protracted negotiations during the summer.
However, with Danny Simpson having rejected the Magpies' latest contract offer with his current arrangement due to expire at the end of the campaign, the right-back position has become a priority.
Pardew is also keen to add a central defender to his squad with injuries and suspensions having exposed the lack of depth among the current crop, while a striker is on his wish-list regardless of Demba Ba's situation.
The manager has not given up hope of hanging on to the Senegal international despite his representatives having held, so far unproductive, talks with Chelsea, but Marseille's Loic Remy is high on his wish-list.
However, sources on Tyneside today played down a link with West Brom frontman Peter Odemwingie.
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