He previously played for the Sydney Roosters, Penrith Panthers in the NRL and was contracted to the St. George Illawarra Dragons, but did not feature in the first team due to serious injury.

Masoe played 12 games for the Sydney Roosters in his debut season as the club reached the 2010 NRL Grand Final.

[10][11][12][13] On 29 June 2015, Masoe signed a two-year contract with the St. George Illawarra Dragons ahead of the start of the 2016 NRL season.

[16][17] Masoe made his Hull Kingston Rovers' début on 6 August 2017, in a 26–22 Qualifiers victory over Halifax at Craven Park.

[18] Masoe was part of the Hull Kingston Rovers' side that gained automatic promotion back to the Super League in the 2017 season.

It was revealed on 26 June 2018, that Mose had signed a new three-year contract extension to stay at Hull Kingston Rovers until at least the end of the 2021 rugby league season.

[19] In January 2020, Masoe was taken from the field on a stretcher during the club's pre-season friendly against Wakefield Trinity after suffering a serious spinal injury.

Due to Masoe's exceptional performances in the 2013 season, he was selected in the Samoan squad and made his début at the 2013 Rugby League World Cup.