The move to keep him at the club will see him remain at the club until the end of 2025, with the Belmore-based operation welcoming him back from injury just over a month ago.
Faitala-Mariner missed all but the entire 2021 season with a foot injury and at one point it was looking as if he may be forced into medical retirement.
The second rower would ultimately make his way back into first-grade in Round 11 this year and has improved his performance week on week, now playing seven games on the trot without incident.
A barnstorming forward, he has played at least 50 minutes in all of his last five games and is averaging almost 100 metres per contest.
Director of football Phil Gould recently said the club were just waiting to appropriately value Faitala-Mariner before offering him a new deal after returning from injury, and they have now completed that process.
"There was a lot of uncertainty with the setbacks that I had," Faitala-Mariner said in a club statement.
"The club has shown a lot of faith in me being away from the game for a year and a half. Phil Gould has been really good, messaging me every fortnight to see how I am."
He said he was excited to now be a senior player in the squad.
"Now that I'm one of the older heads in the squad, you know, we have a lot of young fellas coming through," Faitala-Mariner added.
"What can I do to bring the best out of these young fellas, so that we can move in a direction where this club can be in a successful again."
Intriguingly, with the club signing Viliame Kikau for 2023 to join Tevita Pangai Junior next year, it would now appear the former Bronco Pangai Junior will play in the middle third to accommodate Faitala-Mariner starting, as well as young gun Matt Doorey returning to first-grade after spending the first half of this year injured.
Faitala-Mariner has played 92 NRL games to go with three Tests for Samoa and one for New Zealand.