Rosmini, a career policeman, played as a left-sided midfielder for the football team of the
Royal Brunei Police Force. His performances in the international scene caught the eye of
Mick Jones who drafted him into the
Brunei M-League squad in 2001. He scarcely played for the Wasps due to work commitments and his preference to play at domestic club level for
Brunei DPMM FC who signed him in 2003. He won the
Brunei Premier League in
2004. His solitary goal for Brunei came in a 1–1 draw against
Kedah on 20 March 2005. A year later, Rosmini's club moved to the
Malaysia Premier League for the
2005–06 season to replace Brunei. DPMM immediately won promotion, and in
the following season, finished third in Malaysia's top tier. Unfortunately, he was axed along with
Affendy Akup and
Zulkefly Duraman to make way for four Malaysian players in the
2007–08 Malaysia Super League. Rosmini joined newly formed
AM Gunners in the 2008 Brunei Premier Two and became league champions, gaining promotion to the top flight. AM Gunners left the Bruneian football league system in 2011 after two seasons. Rosmini next moved to and captained a reformed
MS PDB, returning to his first club in some ways. After a two-season hiatus, he re-appeared for the Policemen in the
2017 season. After sitting out the first round of the
2018-19 Brunei Super League, Rosmini joined
Kasuka FC in January 2019. ==International career==