However, he had a steady campaign from Taranaki in the Mitre 10 Cup, and played for New Zealand Maori on their end-of-year tour, showing positive signs for a solid Super Rugby season in 2018.
After that, his future is up in the air, and French rugby publication Midi Olympique have reported that Toulouse are on the cusp of claiming his signature.
Ngatai could be opposing Messam in 2018, with the 33-year-old flanker also receiving attention from French clubs.
The 43-test All Black has played 161 games for the Chiefs, the most in franchise history and the fifth most appearances by any player in Super Rugby history.
He is signed to play another year with the Chiefs in 2018, but that could be his last season in the Waikato, with French club Lyon reportedly keen on his services for the 2018-2019 Top 14 season.
Lyon currently have three New Zealanders on their roster, with Josh Bekhuis, Rudi Wulf and Toby Arnold currently playing for them, while NZ-born former Wallaby Mike Harris also plays for the club.
Only promoted back to the Top 14 for the 2016-2017 season, where they finished 10th, Lyon are having a fantastic season so far, currently sitting in third with seven wins and five defeats.