In his first season, he was part of the club starting line up in the 2005 Singapore Cup final where Woodlands Wellington lost 3–2 to Home United.

On 9 December 2011, Isa was announced as a player for the newly created club, LionsXII which will compete in the 2012 Malaysia Super League.

In January 2016, Isa moved to rivals, Geylang International for the 2016 season where he was named as the club captain for the campaign.

On 29 February 2012, he scored his first international goal in a 7–1 lost against Iraq during the 2014 FIFA World Cup qualification at the Grand Hamad Stadium.

As part of the ‘Coaches Overseas Attachment’ pilot programme by 'Unleash The Roar' football project, Isa alongside Noh Alam Shah embarked on an overseas coaching attachment with Japanese top-flight club Tokyo Verdy of the J1 League.

[4] Isa used to front the football side of things for German-sportswear company, Adidas in Singapore along with other teammates in the national team like Lionel Lewis.

In 2020, He has switched over to Puma along with other Singaporean footballers such as Shi Jiayi, Juma'at Jantan, Lionel Lewis and Erwan Gunawan.