The Barbarians squad trained earlier in the day at Marist RFC Park in what was their third day together as a squad.
Matich said the squad are in great spirits ahead of the enormous fixture.
"We're feeling pretty positive. Obviously we've identified the Lions have a strong scrum, but we're definitely not going in like we are going to lose in that area," he said.
"We're trying to figure out how we can win the scrum. There's a whole lot of positivity and that's what we need if we want to go in and win this one.
"No one goes out there to lose, obviously.
"As an individual it's a huge opportunity especially for us guys who aren't fully contracted.
"We're just on three month contracts so it's a huge opportunity to get exposure in New Zealand and overseas."
Barbarians assistant coach Roger Randle concurred with Matich, saying they aren't going into the match to make up numbers.
"We're New Zealand rugby players, every New Zealand team has that winning mentality built in," he said.
"We're not going out there to come off second best but we're well aware of the challenges we face with the calibre of players that are coming.
"We've got a great bunch of guys in our group. We have a couple of experienced guys who have been at the Super level and we have a helluva lot of young players wanting to become Super players who will announce themselves to the world on Saturday."
Randle said the excitement was bubbling within the unit and they were wary of overplaying their hand.
"We're just trying to throw a simple plan together, trying to not complicate things.
"There are challenges with not spending a heap of time together but we knew that going in so it's not really something we've spoken about other than when we first came together.
"We'll just try to keep things simple but throw in a bit innovation.
"It's been a long time coming; we've been in preparation for months as a group.
"We're massively excited."
The Provincial Barbarians starting lineup will be announced on Thursday ahead of the first match of the tour. The British and Irish Lions lineup will also be named that day.
Northland could potentially have three players lining up on Toll Stadium. Matich and lock Josh Goodhue are in camp with the Barbarians while former Taniwha captain Jared Payne could pull on the red Lions strip on his old stomping ground.
The match kicks off at 7.35pm on Saturday. Tickets are still available.
New Zealand Provincial Barbarians squad: Forwards:
Aidan Ross (Bay of Plenty)
Tolu Fahamokioa (Wellington)
Sam Anderson-Heather (Otago)
Andrew Makalio (Tasman)
Marcel Renata (Auckland)
Oliver Jager (Canterbury)
Keepa Mewett (Bay of Plenty)
Joshua Goodhue (Northland)
James Tucker (Waikato)
Mitchell Dunshea (Canterbury)
Lachlan Boshier (Taranaki)
Matthew Matich (Northland)
Peter Rowe (Wanganui)
Backs:
Jack Stratton (Canterbury)
Richard Judd (Bay of Plenty)
Bryn Gatland (North Harbour)
Dwayne Sweeney (Waikato)
Kaveinga Finau (Inga) (Canterbury)
Jonah Lowe (Hawke's Bay)
Sevuloni Reece (Waikato)
Sam Vaka (Counties Manukau)
Luteru Laulala (Counties Manukau)
Junior Ngaluafe (Southland)
