Holmes, who played 21 Tests for Australia, injured his ankle just after halftime in St George Illawarra's 24-22 win over Parramatta last Sunday.
Initial fears of a syndesmosis, or high-ankle sprain, meant Holmes's Cook Islands debut might have to be put on ice.
But Iro, who is preparing for Cronulla's elimination final against North Queensland in week one of the NRL finals, said the diagnosis was looking far better 48 hours on.
"I saw him yesterday and I think it's a low-grade sprain so he'll be sweet to go," Iro told media after the Sharks' training session ahead of Saturday night's final at Sydney's Allianz Stadium.
"Ah, I'm not sure if I'm meant to say that, but he did tell me he was sweet so that's pretty good."
Iro has played 11 Tests for the Kuki Airani although his family's international pedigree was heavily slanted towards New Zealand since the Cook Islands didn't join the International Rugby League (IRL) until 1998.
His uncle Tony Iro played 25 Tests for the Kiwis, while father Kevin Iro played 34, although he managed four Tests for the Kuki Airani towards the end of his career, including the 2000 World Cup.
"I'm pretty excited - I haven't spoken too much to the coach (former Australian fullback Karmichael Hunt) yet, but I'm always privileged to put that jersey on," Iro said.
"It's massive for me because I grew up there, so my heart is tied to there. It makes me happy to represent Cook Islands."
Their first game of the 2026 World Cup is against Fiji at Newcastle's McDonald Jones Stadium on October 18.
But first, Iro has unfinished business with Cronulla.
He has played all six finals with the Sharks in 2024 and 2025 reaching the preliminary finals both years only to fall to Penrith and then Melbourne respectively.
The Sharks also enter the 2026 finals race having lost three of their last four games.
"I feel like finals is a whole new contest. You don't look at the past but focus on what's in front of you," Iro said.
"We have made prelim finals the last couple of years, which is pretty good, but we're always chasing more.
"It is good to have Tricky (five-eighth Braydon Trindall). He's so energetic, a real ball of energy on the field wanting to be part of everything."
Iro actually scored a hat-trick the last time the Sharks faced the Cowboys although they lost the round-eight contest 46-34.
Perhaps Iro's midas touch might return at Allianz Stadium.
"I hope so because I haven't scored one (try) in a while," he said, with his last four-pointer seven weeks ago in round 21."
