He was signed after a pair of impressive performances, first against the Crusaders off the bench and then a start against the Blues.
The former Crusader has already clocked up more game time this year than his final campaign with the red-and-blacks in 2017.
“It’s pretty overwhelming as I’ve played more minutes than I did in the entire last season,” Wainui said, who felt his game against the Blues was a turning point.
“It was massive as there were a lot of doubters and I had my own doubts – but it was good to put that performance out there for myself.
“Now that’s the standard and I’ve got to keep going.”
The 22-year-old is more used to playing in the midfield than in the outside backs but is happy to fill in following a season-ending injury to Tim Nanai-Williams.
Yet the New Zealand Maori ace is not a total stranger to the No.14 jersey, having played there against Canada in Vancouver last year.
He said he was looking forward to his first home game for the Chiefs when they clash with the Bulls in Hamilton on Friday.
“It’s just another way I can get better as a rugby player,” Wainui said.
“I’m enjoying being on the wing at the moment and heaps of boys around here have been helping me, so it’s been good.”