"So that makes five bowlers out, our first class player, and all our experienced batsmen," said Marr.
"But I'm actually looking forward to it. Under adversity we step up.
"This could bring the best out in the guys."
Greg Smith will skipper the team, a role he did twice last summer, with Matthew Boswell recalled, while coming back to this level are three familiar faces in allrounders Craig Clare, Fraser Kinnerley and spinner Bryant Galpin.
Smith, having an out-of-sorts season, will have to shoulder a lot of batting responsibility with Boswell, Chris Stewart and Matthew Simes the main backups.
"Everyone can score a 50 at this level, there's no doubt about it," said Marr.
Kinnerley and Galpin have not played for Wanganui for a couple of seasons, with Galpin only rejoining Matt Burke Engineering Marton in the last few weeks, as did Clare after a break from his long 2017 rugby season.
"We desperately cried out for a spinner and [Galpin] was going alright," said Marr.
"The rugby coaches have been on to start training, but [Clare]'s going to play some cricket."
Kinnerley has been in good form in the Bullocks Coastal Challenge Cup, and Marr said the hope will just be to get the ball down on a good length, especially with his brother and the only squad regular Ross Kinnerley possibly not bowling due to needing injections in his sore shoulder.
"We're going to have to get back to what we haven't done very well – that's putting the ball in the right area," said Marr.
"We've been going for five, six runs an over."
Making his debut will be another of Marr's Wanganui Collegiate charges in bowler Ben Kelt, who did play for Emerging Wanganui in November.
"For guys like Ben Kelt, they'll be a lot of pressure, but I'm hoping they can stand up," the coach said.
They will have too, as Wairarapa have experienced the same minor renaissance that Wanganui went through last season.
After a first innings points loss to Hawke's Bay in the opening game and then an innings hammering by Taranaki, Wairarapa picked up a surprise first innings points win over Manawatu, and then made a great comeback to beat Horowhenua-Kapiti by four wickets a fortnight ago.
Bowler Stefan Hook took ten wickets in that game, including seven in the third innings, while captain Daniel Ingham is an allrounder to respect and batsman Brock Price has clocked over 300 runs this campaign at an average of 46.86.
The Wanganui team is
Greg Smith (c), Chris Stewart, Matthew Boswell, Craig Clare, Nick Harding, Matthew Simes, Ross Kinnerley, Thomas Walshe, Ben Kelt, Fraser Kinnerley, Bryant Galpin.