[2] Nsereko joined Kampala City Council (KCC) as a ball boy in the late 1960s, but regularly featured for the club's second team.
[3] Initially deployed as right winger by coach Jaberi Bidandi Ssali, Nsereko shifted in his favoured central midfield role with time.
[4] Nsereko won the CECAFA Cup in 1973, 1976, and 1977;[4] he missed the final penalty in a shoot-out defeat to Tanzania in the 1974 competition.
[3] In April 1989, Nsereko was voted General Secretary of the Federation of Uganda Football Associations (FUFA).
[3] Thanks to the revamp of youth football development, the Uganda national team won back-to-back CECAFA Cup titles in 1989 and 1990.