[4] Sio played junior league for the Marist Saints before he was signed by the New Zealand Warriors.

At the end of the 2013 season he was awarded the Sonny Fai Medal as the Junior Warriors' player of the year.

[6] Sio was called up to the Samoan squad for the 2013 World Cup to replace Masada Iosefa.

On 7 October 2014, Sio was selected in the Samoan side for the 2014 Four Nations series.

[8] However, on 22 June 2015, he signed a 1+1⁄2-year contract with Super League club Wakefield Trinity Wildcats.