The New Zealander knows his side must beat Widnes Vikings by 14 points or more in today’s final Qualifiers game or end up in the dreaded Million Pound Game.
As Hull KR know only too well from their experiences in 2016 - when they were relegated in that fixture at the hands of Salford Red Devils - that is not something any of them want to encounter again.
For Vaivai, who has made such a positive impact since joining the Robins in April, it is all rather alien.
“It’s different to what I’m used to,” admitted the ex-South Sydney player.
“In Australia, you have your top eight and they play-off but the rest are pretty much done for the season and they go home and prepare for pre-season.
“They have international commitments to look forward but there is no relegation so this is different.
“It’s my first time being a part of it and it can be nerve-wracking at times, especially the situation we’re in.
“But we’re not trying to prepare for what could or might happen. We just want to win and do what we need to on Sunday.”
Many of the Robins players have been here before and America international Vaivai added: “I see how much it’s important to them and the desire to make sure they don’t go through that again.
“The boys are in a good frame of mind for Sunday’s game.
“A lot of them have dealt with the disappointment of being relegated and obviously come back up so they don’t want to be in that position where they’re in the Million Pound Game again.
“But if we are, we’ll face that when it comes.”
Vaivai, of course, has a famous cousin - the former wrestler-turned-movie star Dwayne ‘The Rock’ Johnson - who has had a big impact on resurrecting the 28-year-old’s rugby league career.
“There was a point in 2015 where I was just going to hang my boots up and go look for a job,” he explained.
“Basically, all he said to me was ‘go back and play because you want to play not because you HAVE to play.’
“I went back and started again. I started with park footy and loved every moment of it.
“I was lucky to be coached by a very experienced coach in Brett Kimmorley and I just started to enjoy my rugby league again.
“I was fortunate enough to play in the World Cup last year with America and then get this opportunity with Hull KR. I’ve loved it.
“He (The Rock) a fan of rugby. I haven't spoken to him as much since I’ve been here.
“I try not to interfere with his schedule but he’s in London in a couple of weeks.
“My aunty definitely is. I've been in touch with her a fair bit.
“Hopefully I do get a chance to go down and catch up with him.”