From 2013 to 2015, Sipley played for the New Zealand Warriors' NYC team.[5] On 5 October 2014, he played in the Warriors' 2014 NYC Grand Final win over the Brisbane Broncos.[6] He captained the side in 2015.[7] On 2 May 2015, he played for the Junior Kiwis against the Junior Kangaroos.[8] On 3 June 2015, he re-signed with the Warriors on a 2-year contract.[9]
On 19 May, Toafofoa Sipley made his club debut for Manly Warringah against the Melbourne Storm in the 24-4 win at AAMI Park. Sipley made a total of 4 appearances for Manly in the 2018 NRL season as the club endured one of their worst ever seasons finishing 15th on the table and narrowly avoiding the wooden spoon.[14]
On 27 October, Sipley made his debut for Niue against Italy. In this match, he scored a try as Niue lost 36–32.[15]
Sipley made no appearances for Manly in the 2020 NRL season. In round 16 of the 2021 NRL season, he scored two tries for Manly in a 66-0 victory over Canterbury.[17]
Sipley played 20 games for Manly in the 2021 NRL season but did not feature in their finals campaign which saw them reach the preliminary final stage before losing to South Sydney.[18]