Born in Nigeria Okolosi played for Julius Berger F.C and transferred to the Côte d'Ivoire and joined Africa Sports National.
After playing in one test match Okolosi made his domestic league debut for the club in the home game in the St. Jakob Stadium on 19 July 1995 as Basel won 2–1 against Sion.
At the end of October Andrey lost his job and was replaced by Karl Engel who changed the team and put Okolosi on the substitutes bench.
[3] In the 1996 offseason Okolosi transferred to BSC Young Boys, but did not get as much playing time as with his former club, so the following summer he moved on again.
Following these three years in Europe Okolosi moved to Tunisia and joined Espérance Sportive, where he stayed for one season.