He previously played for Glasgow Warriors; and the New Zealand sides Otago - in domestic Mitre 10 Cup - and the Highlanders - in the international Super Rugby competition.
He captained the school's first XV rugby side in his final year before going on to play once for South Canterbury in the Heartland Championship while he was still a college student.
After debuting in a match against local rivals Southland in week 3 of the competition, he went on to play 7 times throughout the year as the Razorbacks reached the Championship final before being thrashed 41-16 by Counties Manukau.
Injury to fellow loosehead Craig Millar meant that he started all 10 of Otago's games in what proved to be a difficult year which ended up with them finishing in 6th place on the championship log and missing out on the playoffs completely.
[9] He finally made his Super Rugby debut in an impressive 26-13 victory over the Chiefs in Hamilton on 7 May 2016 and went on to play 7 times in total during the year as his side reached the tournament semi-finals before going down to the Lions in Johannesburg.
[14] On 29 May 2021 Seiuli was named in the Samoa international squad - alongside his then team-mate at Glasgow Warriors, TJ Ioane - to play the Maori All Blacks and Tonga in the summer of 2021.