"It's important we give Clive the respect they deserve."
Duff, who at 20 is three years younger than his brother, has shifted to the No 12 spot after playing on the wing in last week's semifinal as the riversiders have lost world champion Baby Blacks first five-eighth Tiaan Falcon to Saracens duty and Magpies centre Jonah Lowe to injury.
"It's so I can be closer to Joe," Duff quipped.
"Seriously Joe has run down my channel a lot when I've been in the 12 role before. I managed to tackle him once ... I know I have to go low if I'm first there and hopefully some of my teammates will then go high and finish him off," Duff explained.
The pair, who still live with their parents and three of their five siblings, played their junior rugby with NOBM. But Duff ended up at Clive because several of his St John's College teammates - including Jonah Lowe and Etu Tuanaki - linked up with the riversiders. During Joseph's final year at school the pair played in the 1st XV together when Duff was in year 10.
"We're really confident we can do the job but at the same time we know we have to play for 80 minutes and go hard. These NOBM guys are just too fit," Duff said.
Duff admitted the Clive forwards had discussed in detail the methods which would be used to shut his brother down. While he has the Hawke's Bay Samoans rep team programme to focus on after this week, his brother is still unsure about his rep season.
"I have to play well this weekend and hopefully I might get a run for the Magpies against Manawatu next week. If I don't there are other options," Joseph said.
"At the moment I'm just focused on making sure Duff ends up with the cooking and cleaning duties for the rest of the year," he said referring to the bet which is at stake on the result of the final.
When quizzed if the pair will continue to play for different clubs Joseph pointed out Duff may be told to return to the Green Machine's camp within the next season or two.
"Clive have been good to Duff but it's tough on our dad [Sefo] trying to watch both of us during the season. For dad's sake we might play together soon."
NOBM head coach Craig Gowler was forced to promote halfback Liam Batt from the club's colts team when Zac Donaldson was called into the Saracens team for today's match against Waikato in Taupo in the wake of clubmate Ellery Wilson's injury.
"We will miss Zac and Ellery but Liam has fitted in well. This will be the biggest game of Liam's life but he had a season of premier rugby for Pirates last year, he'll be fine," Gowler said.
Clive head coach Blair Cross said he had no qualms about losing Falcon to Saracens duty.
"We knew all along we would lose contracted Magpies. Had Jonah [Lowe] been fit we would have lost him too."
"We know NOBM have set the standard for the past two seasons but we're approaching the game with a positive mindset. It's no secret we will try and take them on up front. If we do the things we know we can do well we will have a shot. The only time our pack has been bullied this season was when we played NOBM last time so there will be no lack of motivation."
Cross said his troops were keen to give veteran prop Nathan Bruce the send-off he deserved after 15 years of service.
"Nathan is going to leave a big hole."
Teams for the 3pm match:
NOBM: Liam Edwards, Sammi Lauano, Migao Lauano, Paul Bickle, Craig Sharplin, Johnny Lauano, Liam Batt, Joseph Penitito, Chris Johnston (c), Jack Nelson-Murray, Hannon Brighouse, Matt Gardner, Jarvy Aoake, Terry Marsh, Chris Benson. Substitutes, forwards: Morunga Whaanga, Mike King, Ricky Hayes, Willy Benson, Sean Skeet. Backs: Sam Weber, Jared Travers.
CLIVE: Charlton Karauria, Elijah Tuavera, Jordan Pineaha, Duff Penitito, Sakopo Ofa, Tianua Poto, Bronson Hokianga, Karl Lowe, Lucas Goodin, Api Sione, Rana Huata, Josh Eden-Whaitiri, Kereama Peni, Jorian Tangaere (c), Nathan Bruce. Substitutes, forwards: Tinirau McIlroy, Tali Faiumu, Beau Tresidder, Shannon Hawea. Backs: Moses Riley, Cory Tautau, Peter Bassett.