Witcombe also said that the Friday game would be a bit of a showcase for local players, who often seemed content with being good against average opposition without pressing on to challenge themselves, and find out where the bar really stood.
He agreed that often coaches could tell players what they need to do with the likes of attention to detail, but it was up to the players to make the next move.
"It'll be an eye-opener for some of them.
"We can bark all we like as coaches but, at the end of the day, it's got to be the players who do the work, it'll take time for everyone to realise that but it's happening, which is great.
"I think you only know what you know. Friday night is a good opportunity for some of these young guys to know what is required for that next level."
For Witcombe and assistant coach George Konia, the match is not about trying to upset a Super Rugby team, instead it is about keeping it simple.
Of the squad that was available, from which a team would be picked this evening, a lot of ITM Cup players were not included due to injury.
Witcombe said the tactic would be to keep it simple due to the limited build-up they had had, with the penultimate Harding Shield round taking place last weekend, but he expected the ball to be thrown about a fair bit.
He also encouraged Northlanders to get down to Toll Stadium to support the team, saying it seemed like an ideal way to spend a Friday night.
For his part, Northland Rugby Union chief executive officer Jeremy Parkinson said it was satisfying to see the clash happen after the Blues took away the regular pre-season clash, instead preferring to travel to New South Wales.
Parkinson felt this Friday's game against the Blues was a better option, citing the fact that there would be more Northlanders playing in front of a home crowd.
He also hoped Northlanders wouldn't let a little bit of rain put them off from turning out on Friday evening.
"We believe if the weather clears there's a good anticipation we'll get a good walk up crowd. The more the merrier. It'd be good to get people to come and support."
Parkinson added the work from the Blues management and local sponsors had ensured the game was possible.
He said the Blues would bus up the morning of the game and travel to Kamo, Whau Valley, and Morningside Primary schools in preparation for the match.