"Junior could have gone with Dev [Wanganui Toyota Development XV].
"Fa'alele, I think he would have been real good in the Heartland - a nippy little guy, coming on in the last 20 minutes."
Hamlin said Iosua was dead keen to come back to play for Wanganui, but was unable to secure a visa extension - a matter that will have to be sorted out.
The irony of needing a second halfback behind Lindsay Horrocks is that his 2016 understudy Kane Tamou is now looking to cement his place in the Horowhenua Kapiti lineup.
Tamou, who was strong in his selective opportunities during last year's undefeated march to the Meads Cup, transferred from the Ratana club to Foxton early in the Tasman Tanning Premier club season in the hope of becoming a No1 provincial halfback.
"You can understand that," said Hamlin.
"Kane was living in Palmerston North as well. You saw, when he didn't make the mid-season squad, he thought, 'I've got to go out and try', so good on him."
There could well be another reunion at Playford Park as 2015 Wanganui front rower Tawhio Gupwell, now with the Rahui club, is one of seven props currently getting a look-in with Horowhenua-Kapiti's wider squad.
The side will be captained by very experienced lock Ryan Shelford.
Wanganui had better news on the injury front as their influential lock/loose forward Fraser Hammond is back from injury, but Campbell Hart will still need at least another week to be fully fit from his groin strain.
The Cup being on the line adds a little flavour to the preseason clash, given Horowhenua Kapiti took it off Wanganui at Cooks Gardens in 2014, before Wanganui regained it in Levin for captain Peter Rowe's 100th game in 2015, then narrowly defended it last year in the final round robin match.
Kickoff in Levin is at 2.30pm.