The other empty space is for a forward and has yet to be confirmed.
Caskey said the return of Auckland's Rhema Sagote and Manawatu's Tevita Taufui to the midfield had been about re-establishing old contacts and being former Wanganui players they should have an easier acceptance locally.
"You know what you're getting too, which is good," he said. "You usually get these guys blind. We knew what Tevita could do from the Turbos, Rehema was a shot in the dark [in 2012]."
Taufui had told Caskey he was going to miss selection for the Manawatu ITM Cup team this season and he was keen to come back.
"We've been working with Rhema for a fair while, quite a few months, and he's been reasonably keen the whole time," Caskey said.
The loss of Nick Cranston, along with Simon Hillis as his potential understudy, has been a blow in the locking department in terms of height and bulk, but Caskey is confident they have this area covered.
He will chat with soldier Sonny Woodmass this weekend, but believes army duties will not keep him away this campaign as they did in a handful of 2013 games.
Nor is the door closed completely on the two players most unlikely to have missed selection - Border's top season points scorer Sikeli Ulukuta and Ratana's inspirational prop Vaan Rauhina, who reached 50 games while captaining Wanganui a couple of times last year.
Caskey said Ulukuta still saw himself more as a loose forward after a club season on the wing, where the likes of CJ Stowers and Jaye Flaws have been progressing well. "Bobo's definitely got talent, but he's still pretty young."
He had likewise spoken to Rauhina, who vowed he would continue putting in to play well alongside Ulukuta and others in the Wanganui Development XV, should his chance come to return, always a likelihood through injuries.
"You want to see the guys working hard and not dropping their lip," Caskey said.
The selectors decided to elevate the young Kamipeli Latu and Viki Tofa while keeping one veteran in Shaun McDonough, who played a bit of Senior and Premier rugby to get his fitness up.
"It came down to one of the two [veterans].
"Vaan was in the reckoning, but in the front row we're trying to build a bit of youth.
"Prop's a weak spot in the union at the moment and you can't keep thrashing those same guys."
McDonough and club mate Andrew Evans had not featured much in the Wanganui squad buildups, but Caskey said that like Rowe, having watched them for 7-8 years, he just wanted to get the lay of the land elsewhere and make sure no stones were unturned. "It was not the fact they weren't in the reckoning, it was more about what's new on the scene."
The team goes into camp at 10 this morning, and will bus to Turangi on Saturday, arriving around midday for the 2pm game.
Focus for the weekend will be working on coming into contact and defence patterns as a team, while formulating their style of attack with this new-look backline.
Caskey will discuss with King Country coach Kurt McQuilkin whether they play 20 minute quarters or perhaps a two-quarter first half and full second stanza, seeing as the home side is likely to want to give around 25-26 players a run.
This is an appropriate opponent for Wanganui's first hit out as it was King Country who inflicted a 17-16 defeat at Cooks Gardens last August.
