Born in his native Suvai, Samoa, once he immigrated to Sydney, Australia, Lafai attended Sarah Redfern High School, graduating in 2009 while playing his junior football for the Minto Cobras and Campbelltown Warriors. In 2007, Lafai played for the Western Suburbs Magpies' Harold Matthews team before being signed by the South Sydney Rabbitohs. He played for the Rabbitohs' SG Ball team and also played for the Campbelltown Eagles in the Bundaberg Red Cup.
After the 2009 season, Lafai signed a 1-year contract with the Canterbury-Bankstown Bulldogs. He played for the Bulldogs' Toyota Cup team in 2010 and 2011, scoring 17 tries and 17 goals in 32 games.
At the end of 2011, Lafai was named on the interchange bench in the 2011 Toyota Cup Team of the Year.
Lafai attended Sarah Redfern High School in Minto, New South Wales, graduating in 2009.