The 101kg Ropiha, who is 9kg lighter than Pohatu, will be trained by Napier Boxing Club trainer Ryan Whittaker for the bout which is scheduled for three two-minute rounds.
"Obviously getting in close will be important for me as Rocky will have the bigger reach. But just as important will be sticking to the game plan Ryan designs for me ... everyone knows how easy it is for novices like us to go crazy once we step into the ring."
Pohatu, 25, has already had three training sessions with another of the Bay's successful trainers, Hawke's Bay Today's 2013 Person of the Year Craig McDougall.
"Different levels of fitness are involved and you use different muscles to those used in rugby training. I've also had a couple of sparring sessions with a couple of cousins," Pohatu said.
When quizzed if the fact he has the same name as Rocky Balboa, a boxing character portrayed in a series of films by Sylvester Stallone, could prove an advantage Pohatu replied:
"That might be a handicap. My dad [Tamati] named me Rocky and while those films might have had an influence I'm sure it wasn't the only reason. Like Billy I'm just happy to be getting into the ring for a good cause."
Funds raised from the 12-bout event will go towards the Jarrod Cunningham Trust and the Nga Tukemata O Kahungunu Vocational Trust which helps disabled adults.
Kiwi rapper and hip-hop artist Sid Diamond, who has been Hawke's Bay-based for the past 18 months, will provide the halftime entertainment. This will be his first major gig since moving to the Bay from Auckland.
Diamond, 29, will perform three songs and will ask fans a week out from the show what they want to hear.
"I think that will be better than doing songs they don't want to hear. I can't wait to see people who haven't boxed before do something like that."
A former basketballer, Diamond, does mountainbiking to keep fit these days. Previously known by his stage name Young Sid, Diamond, is a member of hip-hop group Smashproof. Before the show his biggest priority will be working in the studio to complete his latest EP which he began two months ago.
Co-organiser of the event, Magpies halfback Chris Eaton, will announce the main feature bout later this month. Former professional Jason Rarere has come out of retirement to take on former kickboxer Shaun Rankin in one of the clashes.
-Tickets are available from TicketDirect.
The card:
- Ellery Wilson (Napier Old Boys Marist) v Colin Hokianga (MAC).
- Lance Wiparata (Maraenui) v Tianua Poto (Clive).
- Sam Matson (Havelock North) v Lewis Marshall (MAC).
- Reece Aranui (Taradale) v Clinton Vaiusu (MAC).
- Billy Ropiha (Taradale) v Rocky Pohatu (Clive).
- Rhiarna Ferris (Havelock North) v Te Mahia Raureti (Tamatea).
- Dillon Clark (Napier Pirate Rugby and Sports) v Nathan Pulega (Napier Technical).
- Ted Walters (Napier Technical) v Mike Ward (Hastings Rugby and Sports).
- Jason Rarere v Shaun Rankin.
- Three more bouts to be announced.