Early years and Asante Kotoko Born and bred in Asawase a suburb of Kumasi, Osei started his career with
Suame-based Anokye Stars a colts football team, before joining Neoplan Stars, both in Kumasi. He moved to
Nkawkaw-based club
Okwawu United F.C. in the 1980s and played alongside his cousin
Tony Yeboah, he later moved to Kumasi Asante Kotoko in 1989. He won the
Ghana Premier League twice during his stay with the club, in 1991 and 1992.
Vorwärts Steyr In the later part of 1992, Osei moved outside Ghana and signed for Austrian team
Vorwärts Steyr. He played for the club for one season. He made his league debut on 15 March 1992 coming on as a substitute in the late minutes of a 1–0 win against
FC Blau-Weiß Linz. He continued to play for club in the
Austrian Bundesliga making five appearances in his debut season in the
1992–93 season and went on further to make eight appearances in the
1993–94 season, bringing his total number of league appearances to 13 before leaving the club.
Eintracht Frankfurt Osei moved to Germany and transferred to
Eintracht Frankfurt in 1993, in the process joining his Ghanaian colleague, former teammate at Okwawu United and cousin
Tony Yeboah.
Caracas In 1996, Osei joined,
Venezuelan Primera División giants
Caracas F.C. playing in
1995–96 season and featuring in the
Copa Libertadores for a season. He made four appearances in
1996 Copa Libertadores.
Mainz 05 After leaving Caracas FC, Osei joined
Mainz 05 in 1996 and in the process being in the same squad and playing alongside people like German coach
Jürgen Klopp,
Torsten Lieberknecht,
Bruno Akrapović, and
Dimo Wache. He played for the club for one season making five appearances scoring one goal in the
2. Bundesliga. He scored his only goal with the club in a match against
1. FC Lokomotive Leipzig on 6 August 1996, the match ended in a 2–1 home win. He left the club in 1997.
Later career Osei joined now defunct Turkish club
Vanspor in 1997. After leaving Vanspor in 1998, Osei went on to play for German lower tier sides
SC Weismain-Obermain for a season,
Viktoria Aschaffenburg for a season, for three seasons,
SV Erlenbach for two seasons and finally retiring after playing one season with
Alemannia Haibach in 2006. == International career ==