"We're looking at getting a squad that is capable of playing the rugby we want to play.
"All rugby starts up front. The tight five is a big thing we're looking at.
"Making sure our attack is up to where we need it to be as well."
After the Top 5 players in the Premier MVP list were all loose forwards, Caskey is confident he will have the depth available without previous incumbents Jamie Hughes (injured) and Angus Middleton (unavailable).
"There's plenty of competition in there. We've got some good-enough numbers."
Notably, the selectors have looked outside of Premier with nine players from Senior-grade clubs Ratana, Utiku Old Boys and Hunterville offered opportunities, while others played a mixture of Senior and Premier rugby this year for the bigger clubs.
"Realistically, as a union, we need these teams to carry on and get stronger, and at some stage get back to Premier rugby," said Caskey.
"Honestly, six teams is a worry.
"These guys need to push themselves, every time [a club] drop a level, naturally you will drop a level as well."
There could be an opportunity for a Senior bolter to make the Heartland squad, or at least keep himself in the frame by playing for the Whanganui Development XV and getting a higher level of training and development.
"It's a flow-on effect to take it back to their clubs, and make their clubs stronger," said Caskey.
"It would be good to see eight good teams in the Prems – makes it easier for the Heartland coaches."
Regarding attacking rugby out wide, making his return as a Player of Origin is Kameli Kuruyabaki, a 2016 and 2018 Whanganui rep in between stints in Manawatu, now with the Te Kawau club where Caskey said he had a good season.
Kuruyabaki provides depth, which the selectors have also looked to cultivate with squad allocations – because there are Marist and Ngamatapouri players who will be "Country" players this weekend.
"You've got to make sure you're spreading the talent as well. Country are short in some positions, and too many in Town."
Ratana players also appear on both teams, but Caskey said all other affiliations go on the backburner for the next few months, as everyone shares common purpose.
"There's no clubs when you come into the Heartland team."
The Country team trained under Ruapehu coach Kim McNaught in Ohakune on Wednesday, while the Town side met with Marist Celtic coach Duane Brown and assistant Cornell Mason at Cullinane College on Thursday.
Kick-off is 2pm.
The invited players are:
Town
Forwards – Viki Tofa (Marist); Ranato Tikoisolomone (Border); Eddie Tataurangi (Ratana); Faith Esera (Kaierau); Brendan Hemana (Border); Joe Edwards (Kaierau); Jack van Bussel (Kaierau); Josh Lane (Kaierau); Matt Ashworth (Kaierau); Josefa Rokotakala (Kaierau); Jack Hodges (Border); Cade Robinson (Kaierau); Semi Vodosese (Border); Kieran Hussey (Border); Western Hemi (Ratana); Woody Martin (Kaierau).
Backs – Lindsay Horrocks (Border); Cameron Davies (Kaierau); Ethan Robinson (Kaierau); Rangi Kui (Marist); Bernard Matthews (Ratana); Andy Hamilton (Border); Josaia Bogileka (Marist); Dillon Adrole (Kaierau); Alekesio Vakarorogo (Border); Harry Unsworth (Kaierau); Tom Symes (Border); Remi Halpin (Ngamatapouri); Nick Harding (Border); Ezra Malo (Kaierau).
Country
Forwards – Hadlee Hay-Horton (Taihape); Gabriel Hakaraia (Ruapehu); Gordon Coogan (Utiku); Shade Tuaine-Whanau (Marist); Roman Tutauha (Ruapehu); Jack Yarrall (Marist); Peter-Travis Hay-Horton (Taihape); Mark Coogan (Utiku); Brad O'Leary (Marist); Joeli Tora (Ngamatapouri); Campbell Hart (Ruapehu); Ben Whale (Taihape); Brad Graham (Marist); Matt Brown (Taihape); Tawhiwhi Karaitiana (Ratana); Regan Collier (Taihape); Jack Kinder (Ruapehu).