The Super Eagles of Nigeria slipped three spots from 42nd in the world to 45th in June and the latest ranking published by the world governing body.
Despite holding firm to third spot in Africa, Nigeria failed to pick from their impressive jump back in April when the country moved four places in the ranking.
Meanwhile, Senegal are still the best team in Africa and are ranked 22nd in the world, with Tunisia in second and 25th globally.
The top three sides will take part in hostilities on the continent this month in Egypt when the Africa Cup of Nations gets under way.
Nigeria is in group B alongside Guinea, Madagascar and Burundi.
These teams will be heading to AFCON ranked 13th (71), 25th (108) and 37th (134) respectively.
Only Burundi in the group moved up stepping up two places, while Guinea dropped three spots and Madagascar also slipped by a spot.