Likewise, four other players are unavailable through university exams and other reasons, while the overnight rain last Friday hampered what would have only been the third round of Coastal Challenge Cup cricket for the squad members to find form.
"We've put the team together of the guys that are available. We're underdone - having Chapple Cup at this time of the year is of no benefit to us," said Gillespie. "We've had one practice game on grass, coming over there where the wickets are doing a bit more.
"What I'm looking for is continuous improvement. We've had these guys for eight weeks [practicing] indoors.
"I'm not saying we can't beat Hawke's Bay, but at the moment it's a big ask."
All the available batsman who made good to reasonable scores on the artificial wickets at Springvale Park in club cricket have been selected, with the debutant being Englishman Greg Smith.
Although a club opener, Gillespie said they may not start with Smith, with the side having batting ability, at least by local club standards, down to No10.
"We do bat a long way down - it's trying to get the most out of these guys in each of those positions," Gillespie said.
Looking for people to step up, two of the key features which stand out are Ryan Slight's status as the one true strike bowler, as well as Morgan Inness' elevation to the vice captaincy.
Slight started last summer as a promising teenager, making his debut for Wanganui at the same time he played Premier 1 club cricket for the first time, and he impressed by taking apart the top orders of Hawke's Bay and Wairarapa in Hawke Cup games, before breaking down with a side strain against Horowhenua Kapiti.
Gillespie was happy with Slight's enthusiasm at training, but is cautious about expecting too much against Stags-laden opposition who are now aware of the former rookie.
"I told all the guys, it's a fresh start. Ryan did well last year, I think the thing is the [other team's] guys have seen him now.
"We're trying not to rely on one person."
While Inness also takes on more responsibilities, Gillespie said the leadership must come from veterans Fraser and Dominic Rayner - the latter playing in his 13th Chapple Cup tournament.
"It's safe to say Mark's a reluctant captain - for Chapple Cup it's a one-off.
"Making Morgan vice captain is a move to the future. I need to sit down and discuss with him, his future and his goals, having been away at university.
"If at the end of this season we have created another Ben Smith, or two Ben Smiths, I would be happy.
"I would clone him if I could, he's had a great start to the season."
The result of today's match will decide who Wanganui face tomorrow, with the winners from the four games going for the Chapple Cup, while the beaten teams play off for the Cave Cup.
Last year, under coach Rod Bannister and now departed captain Henry Collier, Wanganui put up a fight on Day 1 against favourites Manawatu, setting a competitive 246/5 thanks to Fraser (109 not out) and Ben Smith (75).
They then had Manawatu at 131/5 before Bevan Small hit a quick-fire 96 not out to get his team home by five wickets.
The following day was a heartbreaking one-run loss, as after dismissing Wairarapa for 230, Wanganui were at 177/9 before a defiant final wicket stand between Todd Inness (54 not out) and Trent Hemi, with Hemi being dismissed going for the winning runs in the 49th over.
Today's game starts at 10.30am and the scorecard will be live on CricHQ.