Barrell was with Samurai RFC as their forwards coach and following a successful tournament approached Sione with a view to moving to Saracens.

[5] It was his performance here that led to joining the Tongan national team "Ikale Tahi" for two games, against Japan and Romania, with a defeat and victory respectively.

[6] Along with several other members of the Tongan team, he chose to depart from national duty early in order to ease the mid-season joining in England.

[7] Sione joined Saracens at the beginning of January 2018 to act both as injury and international call-up cover, with an initial contract to the end of the 2018/19 season.

[9] In February 2019, Sione announced his signing by Wasps, in order to receive more game time and to partially fill the position vacated by Nathan Hughes who departed at the conclusion of the 2018/19 season.