Bulgaria's Hristo Stoichkov, the Barcelona striker, has been reduced to light work-outs in training after straining a thigh muscle, but is expected to play.
The Bulgarians, who only qualified with a last-minute goal in a 2-1 victory over France in Paris, hope their previous finals experience will be an advantage, but admit Nigeria are an unknown quantity.
The Africans lost only one qualifying match, but were beaten by Sweden and Romania last month, although they were not at full strength, with their leading striker, Rashidi Yekini, among those missing.
BULGARIA (4-4-2): Mihailov (Mulhouse); Kremenliev (Levski Sofia), Ivanov (Neuchatel Xamax), Zvetanov (Levski Sofia), Hubchev (Levski Sofia); Balakov (Sporting Lisbon), Yankov (Levski Sofia), Lechkov (Hamburg), Borimirov (Levski Sofia); Stoichkov (Barcelona), Kostadinov (Porto).
NIGERIA (4-4-2): Rufai (Go Ahead Eagles); Eguavoen (Kortrijk), Iroha (Vitesse Arnhem), Keshi (unatt), Okechukwu (Fenerbahce); Oliha (Africa Sports), Oliseh (Reggiana), Finidi (Ajax), Amunike (MSV Duisburg); Yekini (Vitoria Setubal), Amokachi (Club Bruges).