Wests Tigers centre Justin Olam has announced his immediate retirement after struggling with a long-term knee injury.

The decision means the premiership-winning centre won't be available to play for the Papua New Guinea team when it enters the NRL competition in 2028.

Olam had been a trailblazer for rugby league in the Pacific nation, starting out playing in his local village with a sand-filled water bottle before becoming the first player to graduate from the PNG Hunters Queensland Cup side to the NRL.

On Friday afternoon, the Tigers were still determining whether they would be compensated for Olam's retirement in the salary cap given injury contributed significantly to his decision to hang up the boots.

Any extra funds could be used to pursue fellow outside back Taylan May, with whom the club has been linked since he was found not guilty on domestic violence charges earlier this year.

The Tigers have two available top-30 roster spots now that cult hero Olam has bowed out.

"I came here hoping just to play one game, and I've been blessed a hundred times over to have played more than 100," Olam said.

"Hopefully, I can inspire a young kid, whether here or back home in PNG, to chase their dreams."

At his peak, Olam was the most devastating ball-running centre in the NRL, helping Melbourne to the 2020 premiership and winning Dally M Centre of the Year a season later.

Knee issues meant his career never quite hit the same heights after joining the Tigers in 2024 in a swap deal for Shawn Blore.

The injury required the 31-year-old to undergo platelet-rich plasma injections last season and undergo surgery over the summer.

Olam barely participated in the 2025 Tigers' pre-season as a result of the injury and did not feature in the opening three rounds of the campaign.

Olam's 117th and final game was Wests Tigers' round-22 loss to North Queensland at Leichhardt Oval last season.

The Tigers plan to honour him in Sunday's round-four clash against Warriors, as well as during the clash against former club the Storm on May 11.

"He will go down as one of the greatest - if not the greatest - players to represent PNG," said Tigers coach Benji Marshall.

"It's been an absolute privilege having Justin at our club, and we wish him and his family all the very best in the next chapter of their journey.