A litany of injuries that Andrew Fifita carried through the NRL season has conspired to end the career of one of the toughest forwards in the game.

The 33-year-old Wiradjuri and Tongan man called it a day after 13 NRL seasons for Wests Tigers and Cronulla in the midst of negotiations to join either Canterbury or Manly for the 2023 season.

"I have made the hard decision to announce my retirement from the NRL," Fifita said.

"I am extremely grateful for all the milestones and memories I have made.

"I can retire knowing I've fulfilled everything I had dreamed of achieving."

While Fifita did inform Cronulla in August this season would be his last at the Sharks, an exit medical before signing for a third club revealed he would require seven operations to correct ongoing injuries.

The MRI scans all but cleared Fifita to play next year, but a diagnosis from Sharks doctor George Pitsis convinced the 2016 premiership hero to retire, according to a NewsCorp report.

The surgeries included cutting out bone and adding tissue on his left knee, straightening his left ankle, reconstruction on both his right shoulder and nose, fusing up a middle finger, and arthroscopy on his right elbow.

Fifita fended off four Melbourne tacklers to score the matchwinning try that secured the Sharks their only flag, then five years later made a brave return to the NRL after a horror lung injury left him in a coma.

Fifita has 10 State of Origins caps for NSW, 10 Tests for Tonga, a further seven Tests for Australia, six appearances for Indigenous All-Stars, and 251 NRL games, including 213 for Cronulla.

"I'd worked with him a little bit in rep footy... the thing that really stood out to me is how much he cares about the club and all of the players," Sharks coach Craig Fitzgibbon said.

"He wears his heart on his sleeve and he embodies everything that we're trying to achieve here at the Sharks."

By Andrew Mathieson