[2] Faitala-Mariner attended Edgewater College and played his junior rugby league for Otahuhu Leopards before being signed by the New Zealand Warriors.

[4] Faitala-Mariner played at second-row in the Junior Warriors 2013 Holden Cup Grand Final against the Penrith Panthers, scoring a try in the 30–42 loss.

[10] In round 15, against the Gold Coast Titans, Faitala-Mariner scored his first NRL career try in the Warriors 36–14 win at Cbus Super Stadium.

[14] On 7 May 2016, Faitala-Mariner made his international debut for Samoa, playing against Tonga in the 2016 Polynesian Cup off the interchange bench in the 18–6 win at Parramatta Stadium.

At one point, the club were sitting second last on the table before upset wins against the Brisbane Broncos and St George ensured that they finished in 12th place avoiding the wooden spoon.

[20] On 23 March, it was announced that Faitala-Mariner would miss the rest of the 2021 NRL season after suffering a foot injury in Canterbury's loss to Penrith.

[21] After more than a year out of the game due to injury, Faitala-Mariner made his comeback in Canterbury's Round 11 loss to Wests Tigers at Leichhardt Oval.