"Obviously I'm going to be backing Fonterra and hopefully understanding the rules of the game as I'm watching."
Rivers didn't need to know all the rules to be confident about his team's chances - as Scott "Razor" Robertson has been confirmed as coach.
Scotty Stevenson has also kindly volunteered to MC the event.
Some other names in rugby were involved, but Rivers remained tight-lipped about who they were.
"I'm going to keep those [names] a little bit of a mystery for now."
Overall, it was going to be a "really fun day" with food, spot prizes, and maybe a few gumboot throws for good measure, Rivers said.
"We are hoping to capture the good Kiwi community spirit out there."
The game was all in aid of a good cause, as the idea came about in response to flooding throughout the South Island in the last few months, Rivers said.
"We just want to offer some support and bring a little bit of cheer."
All proceeds from the event will go to the Rural Support Trust.
The three Rural Support Trusts in affected areas in the South Island are part of a national network of trusts.
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"They've got really good experience and resources to assist rural individuals and communities after these kind of weather events and other adverse events."
Fonterra was also running a Trade Me auction for those who couldn't make it to the game but still wanted to support the cause.
"There's some really cool things on there, all kinds of products, experiences and services that are up for grabs and will go to the highest bidders - and they've been put up by some really generous sponsors," Rivers said.
Items that were on offer included a genuine Black Caps test cricket bat, a 10-person Hurricanes corporate box experience and a spa and accommodation package.
"There really is something there for everyone."
All money raised in the auction will go to the Rural Support Trust, so it was well worth a look, Rivers said.
To find out more check out #Floodraiser for all the listings, or head to the Trade Me charity auction page.
