Fanni drafted in to replace injured Debuchy
Debuchy sustained a thigh injury during Newcastle United's 2-1 Premier League defeat at Wigan Athletic at the weekend.
"He's out for both games. I called up Rod Fanni who will join us in the evening," Deschamps told a news conference.
Olympique Marseille full-back Fanni has five caps for France.
Les Bleus, who are second in their World Cup qualifying Group I, take on Georgia and leaders Spain at the Stade de France on Friday and next Tuesday respectively.