"Taradale ruined my 50th game celebrations with their 26-19 win six weeks ago. We want to retain the Challenge Trophy and we're treating it like an unofficial Nash Cup final because there wasn't one this season," Donaldson explained.
"Obviously if Brad got an All Blacks call up and there was an opportunity in the Magpies for me I would take it," Donaldson said.
A fourth-season NOBM player after helping St Pat's Town College 1st XV win Wellington Secondary Schools premier title in 2015, Donaldson, is confident the Green Machine can pip the Mighty Maroons.
"We just have to stick to our structures, keep a level head and not push anything."
Donaldson also has his own work ons to focus on.
"My big one is to stay vocal on defence. I need to orchestrate the defensive line. Not get in there myself but make sure I put other players into holes."
A 2017 New Zealand Secondary Schools rep during his final year at Napier Boys' High School, Sheild, 20, admitted yesterday he was still pretty sore after playing in the Magpies pre-season win against the Tasman Mako on Wednesday. But it was something another good soak would fix last night.
"I enjoy the challenge of playing against Zac. Competition makes me play so well," Sheild said.
While Sheild has every right to be happy with his form to date this season for the unbeaten Nash Cup champions he is still seeking gradual improvement with his core roles. He pointed out there continues to be a good attitude within the Taradale camp.
"We just want to keep taking every game week by week. This is another one we want to tick off and there is a good vibe there.
"It will be a tough one because they are at home ... but we're up for it."
NOBM head coach Craig Gowler said his troops are eager to use the match as a measure of where they are at in their quest to reach the semifinals.
"Taradale have set the level this year. This game will show us what we need to work on. It's a big game and quite exciting for us."
The hosts will miss the services of inside back Ellery Wilson, midfield back Jack Winson, lock Tyler Symon-Burke and prop Chris Benson who are all injured.
Taradale co-manager Paul Wise said the visitors will play without centre Nick Biss who has a knee injury. Versatile winger Ollie Sapsford will partner Nathan Ramsay in the midfield.
Wise believed his lads will maintain their unbeaten run if they play to their strengths.
In other games Progressive Meats Havelock North should pip Northfuels Central by three points in Waipukurau if they can start with and maintain the same intensity they produced during the final quarter of their loss to Auto Super Shoppe Hastings Rugby and Sports last weekend. Hastings have the potential to beat Tamatea by 23 at Bill Mathewson Park.
Altherm Window Systems Napier Technical should beat defending champions Tremains Andrew Clark Clive by seven at Whitmore Park and MAC have enough ammunition to beat Tanalised Napier Pirate Rugby and Sports by nine at Tamatea Park.