Instead, the 28-year-old is on track for an early return, with coach Nathan Brown confirming they were hopeful Hiku would be available next weekend for their meeting with the Wests Tigers.
It's a welcome development for a side that has been crushed by injuries in recent weeks, and one that Brown said was only possible due to the work ethic of the veteran centre.
"To Pet's credit, he's actually looked after himself really well and he's worked really hard," Brown said.
"When the initial injury happened, we offered Pet another one-year deal to stay with us; the Cowboys offered him a two-year deal and some security. Obviously, we're losing Pet to a different club, and at different times, different players feel they'll just take the easy way out (in that situation), but Pet has knuckled down and probably worked hard than what he's done in the past, now he's got himself into a position where he can certainly play this back part of the year.
"It was a pretty nasty injury that he had, but it shows if you make the right sacrifices and put the right effort in that you can shave some time off."
Brown said the team got indications that Hiku might be able to make a comeback this season about six weeks ago, and Hiku had been progressing well since.
Hiku's impeding return could ease selection headaches for the team's run home, after losing young centre Rocco Berry to a hamstring injury last week, while winger David Fusitu'a remains sidelined with a hamstring injury.
But while the side were looking forward to his return, Brown said it was Hiku's work ethic in trying to return to full fitness that could prove to be a parting gift to the club.
"It's important from the point of view of our squad to have Pet fit. Obviously, we've had our share of bad luck with our experienced players, so for Pet to be available is important," Brown said.
"But it's probably more important because we have a lot of younger players in our squad and in particular a lot of young outside backs who have either started to play this year or played a few games last year, then we have a couple more young outside backs in the squad that haven't played yet this year.
"I think it's probably more important for their careers that they see how Pet's behaved this year because the way you prepare, whether you are injured or not is the key to becoming a very good player and becoming a consistent player.
"If Pet can leave that little bit, the way he handled himself this year, for all those younger kids, that's probably even more important than us getting him back to play this year."
Warriors casualty ward
Expected back soon
Peta Hiku - shoulder (Rd20)
Chanel Harris-Tavita - pectoral (Rd20)
Roger Tuivasa-Sheck - concussion (Rd20)
Out for the season
Wayde Egan - shoulder
Tohu Harris - knee (ACL)
Indefinite
Rocco Berry - hamstring
David Fusitu'a - hamstring
Tom Ale - ankle