Witcombe added the quality of the Blues team they were facing was up there, saying it would certainly be a good challenge.
"It's a strong team, it's their next best team without their All Blacks so they're obviously taking the match serious."
With seven players away on All Blacks duties, two with the New Zealand Under-20s, and several others sidelined through injury, the match will give a number of Blues fringe players the opportunity to push their cases for inclusion on the plane to Perth to face the Western Force on June 28.
After a two-week break from the Blues' last match against the Hurricanes, Blues coach Sir John Kirwan said it was good for the team to have a decent hit-out.
"It's important to get the guys out playing rather than training all the time," Kirwan said. "It's an opportunity to throw caution to the wind a wee bit and play with no pressure on.
"It's also important to give some guys who haven't had a lot of rugby the chance to push for the last three games."
Northland Rugby Union chief executive Jeremy Parkinson hoped Northlanders would get behind the two teams, saying it was the least we could do.
"If the Blues are supporting the Northland Rugby Union by bringing games to Toll Stadium and Whangarei, it's important the Northland public get behind and watch."
The weather forecast for the 6.30pm kick-off is looking decent with rain easing to a few showers in the evening.
Blues vs NZ Barbarians, today, 6.30pm.
Blues: Ofa Tu'ungafasi, James Parsons(c), Angus Ta'avao,
Liaki Moli, Hayden Triggs, Peter Saili, Brendon O'Connor, Joe Edwards, Piri Weepu, Ihaia West, Melani Nanai, Matt McGahan, Pita Ahki, Frank Halai, Albert Nikoro. Reserves: Tom McCartney, Sam Prattley, Sione Mafileo, William Lloyd, Jordan Manihera, Junior Polouleuligaga, Greg Pleasants-Tate, Tom Donnelly.
NZ Barbarians: Justin Davies, Matt Moulds, Will-Griff John,
Shane Neville, Tom Murday, Paul Tuiaimalo, Kara Pryor, Cam Eyre (c), Kurt Davies, Dan Hawkins, Whiria Meltzer, Winston Stanley, Brooke Gilmour, Filipo Nakosi, Dan McCully. Reserves: Jordan Olsen, Namatahi Waa, Dane Rawiri, Miracle Tulua, Josh Goodhue, Jaycob Matiu, Suia Moala, Jason Guthrie, Sione Kite, Matt Tuatagaloa, Mils Taukiavea.