Mafi and his family returned to New Zealand after he left Perpignan at the end of the 2017–18 Top 14 season, with Mafi rejoining Manawatu Turbos for the 2018 Mitre 10 Cup.
Mafi's return to New Zealand was prompted by his exit from Perpignan at the end of the 2017–18 Top 14 campaign, and he subsequently resumed playing for the Manawatu Turbos in the 2018 Mitre 10 Cup.