Northland will also be without another wing Jone Macilai who has broken leg and is out for the season.
"We'll miss them but no one's irreplaceable, no one's bigger than the team. We'll make it work," Witcombe said.
The Northland Mitre 10 Cup squad will be announced on July 19 — two days before the Bayleys club rugby final — and Witcombe says a mix of experience and new players will wear the Cambridge Blue jersey this season.
There could be a few surprises.
"We've left 10 or so contracts (unfilled) and they'll come from club rugby. That's really important. Anyone brought from outside will be Super Rugby players so it gives club rugby players a lot of opportunities which is exciting for the province."
Three to four contracts will be handed to club players selected from this weekend's club semis.
Five home and away games apiece for Northland this year doesn't bother Witcombe.
"It's just the way of the landscape of the competition. We're excited about it, we don't worry about it. Our big thing is we focus on our performance rather than the results."
Northland was the second best defensive team and had the third best scrum last season when the team lost in the semifinal to Wellington and Witcombe wants his team to be 10 per cent better this year.
"Ten per cent is a lot. If we get halfway there, I think it will be really positive. If we don't quite get there, it doesn't really matter. But we set ourselves some high targets, set some goals.
"If we don't get there, it's no biggie but be positive about it and I think that's going to bring in a new level of professionalism here. Last year was a start, we probably exceeded everyone's expectations so I guess the pressure's on a wee bit to emulate that.
"A win will be great but if we concentrate on the results, that breeds anxiety with people, even coaches. So if we focus on performance, get our processes right, focus on performing our individuals roles well then the outcome is hopefully a win. If it's not, it's not too far away," said the former All Black hooker.
Melbourne Rebels first five Jack Debreczeni and Chiefs midfield back Regan Verney will bolster the Northland line-up that will also have seasoned campaigners Rene Ranger, Sam Nock, Matt Moulds and Ross Wright.
Witcombe said the team connected really well with its fans last year and expected the same this season.
"Hopefully if we play well, we going to be connected to the community better. Come to our games. The players really appreciate it.
"Come out in that first game against Auckland. Could be something special. We haven't played Auckland for about 10 years up here so to get them early is a good opportunity as well."