Three-time African Champions, the Super Eagles, dropped 14 places to 57th position in the latest World football governing body ranking, released on Thursday.
With only 601 points, the Nigerian side, which are currently without a coach, also dropped to the 10 position in Africa.
They now lag behind countries like Algeria, Cote d’ Ivoire, Ghana, Tunisia, Senegal, Cameroon, Congo, Cape Verde Island and Egypt.
Meanwhile, Argentina are the new leaders of the World Ranking.
Despite losing to Chile on penalties in the final of the Copa América, the Albiceleste have leapfrogged Belgium and Germany to take the top spot in the world ranking for the first time in seven years.
The newly-crowned South American champions, Chile, have moved up eight positions, only just missing out on a top-10 ranking at number 11.
New entries in the top 10 are Romania (8th, up 4), England (9th, up 6) and Wales, whose win over Belgium in the EURO 2016 qualifiers has seen them surge 12 positions to tenth place.
Twenty-eight teams have managed to climb by more than 10 positions, including Belize (118th, up 37), Copa América semi-finalists Paraguay (56th, up 29), the Faroe Islands (74th, up 28) and Venezuela (45th, up 27).
Other teams achieving their best-ever rankings this month alongside Wales, the Faroe Islands and Belize are Slovakia (15th, up 2), Austria (15th, up 5), Iceland (23rd, up 14), Albania (36th, up 15), the Philippines (124th, up 13) and Guam (154th, up 20).
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