While he missed the preseason fitness training, having only just returned from England, allrounder Fraser Kinnerley was an automatic inclusion.
"Fraser rocked straight back into town and into a 3km run last night," said Bannister.
The squad is mostly familiar faces from last summer's campaign, the newcomers being young United opener Chris Sharrock, who made some good scores in club cricket, and Jonathan Steward, a former Collegiate captain.
To fill out the teams, youngsters Sam Lambert (Collegiate) and Bryant Galpin (Marton) will play to offer them some preseason development.
Bannister said with guys like Sam O'Leary staying to work in the region after school, they want to mould the "keen and green" teenagers who have played, and often struggled, in the past two years, so they can form a team nucleus of 20- to 23-year-olds for coming seasons.
Specifically, he wants to see how they handle a full day of cricket, on the field and off, to work out how to make them concentrate for sessions.
"The other skills we can teach them, but I'm looking at how much they enjoy their cricket.
"All we expect from these players is to turn up and front up."
Bannister has already pinpointed Collegiate's Todd Inness as a future leader, while throwing down the gauntlet to batsman Collier and bowler Nick Blundell, New Zealand U19 players in 2013-14, who simply must deliver at this level.
For Collier especially, on the cusp of first-class cricket for Central Districts alongside Ben Smith, the innings of 30 to 40 will no longer do.
"He needs hundreds," said Bannister.
"I want Nick Blundell to actually lead the bowling group and I want Henry Collier to lead the batting group. I want these guys to read this."
After Sunday's game, Snook and Bannister will name a squad of 13 for the Chapple Cup one-day competition in Napier, October 18-20.
That squad, along with non-travelling reserves, will then have the warm-up of three Twenty20 games in Levin against Manawatu, Upper Hutt, and Horowhenua next weekend.
The training squad is:
Travis Bartels, Nick Blundell, Brett Cameron, Max Carroll, Henry Collier, Mark Fraser, Daniel Gordon, Bryce Grant, Trent Hemi, Morgan Inness, Todd Inness, Fraser Kinnerley*, Ross Kinnerley, Dominic Lock, John McIlraith, Sam O'Leary, Dominic Rayner, Chris Sharrock, Ben Smith, Jonathan Steward, Brendon Walker. *Joined team this week.