Sharks veteran Paul Gallen.

Paul Gallen rejected the biggest offer of his career to leave Cronulla for Newcastle last year because he wanted to remain a one-club player and the Sharks faithful have rewarded his loyalty with a sell-out farewell home game against Canberra on Sunday.

Gallen, who will retire at the end of his 20th season with Cronulla, revealed ahead of his last match at Pointsbet Stadium that the Knights had offered him a lucrative contract, believed to be worth about $750,000 per season, to help their now departed coach Nathan Brown rebuild the club.

Former Sharks football manager Darren Mooney and assistant coach James Shepherd were behind the bid to lure Gallen to Newcastle but he opted to stay and play out his career at Cronulla for less than half the money Newcastle offered.

"I love this place and I thought we had the team to win a comp," said Gallen, who captained the Sharks to their only premiership in 2016. "We made the grand final qualifier last year and just ran into too many injuries, and if you look at the roster we have now we should be further up the ladder than we are.

"Newcastle were rebuilding and I had done it here three or four times. It is hard for senior players when you are rebuilding, there is a lot of pressure on you and a lot of expectation. I just didn't want to deal with it again.

Paul Gallen with Andrew Ettingshausen.
Paul Gallen with Andrew Ettingshausen. ©Nathan Hopkins/NRL Photos

"It was a fair amount of money, a lot of money, but it probably wasn't worth it to me. I would have earned more money in that season than I did in the past two, so it probably wasn't financially the smartest thing to do, but I just couldn't leave the club."

Gallen joined Cronulla under the coaching of John Lang on a deal worth $2,000 and trained alongside the likes of Andrew Ettingshausen and Mat Rogers before debuting in 2001 as Sharks player No.339 in a team that included David Peachey, Jason Stevens, Preston Campbell, Nathan Long and Nick Graham.

In his 344 appearances for the Sharks since, Gallen has seen 193 more players debut for the club (Billy Magoulis became player No.532 in Round 19), won a premiership, played 32 Tests for Australia and 24 Origins for NSW, and become one of the most polarising players in the game.

The 38-year-old was indirectly responsible for punching being banned, has been fined and suspended for on- and off-field incidents and was one of 12 members of Cronulla's 2011 squad sanctioned over the peptides scandal that engulfed the club.

As the Blues captain during Queensland's era of Origin domination, Gallen was an unpopular figure north of the border but he endeared himself to many because of a willingness to learn from his mistakes, accept responsibility, speak from the heart and the passion he displayed for his team.

Asked to nominate his proudest achievement, Gallen said there were two.

"Sticking through thick and thin with NSW, and that tough time we went through with that great Queensland side. Turning up year-in and year-out and doing my best to try and lead that team to a victory and eventually getting there [in 2014]. That was a really proud moment," Gallen said.

"But also sticking with this club. I had opportunities to leave for more money, right up until 2017 and I stayed here because I love the club and I love what it is about. It is just a home-grown type of club, it is not a rich and famous club, and that is what I am about."

The Sharks celebrate Paul Gallen's most appearances record.
The Sharks celebrate Paul Gallen's most appearances record. ©Gregg Porteous/NRL Photos

He twice had the chance to join Manly, in 2007 and 2010, but was loyal to Ricky Stuart, who had the greatest influence on Gallen's career, along with his successor Shane Flanagan.

It was Stuart who took Gallen to see the legendary Ron Massey in 2009 after a series of incidents, including raking at the stitches of Gold Coast forward Anthony Laffranchi after a tackle and racially abusing St George Illawarra prop Mickey Paea, that cost him the captaincy and more.

"When Ricky was around I was probably getting into a bit of trouble and getting suspended, and doing lots of things I probably shouldn't have done," Gallen said.

"People forget I lost the captaincy here in 2009 and I didn't get it back until 2011. There was the Lafranchi thing and another suspension, and then the Mickey Paea incident.

"Ron Massey really helped me, just to realise my potential and stop being such a goose on the field but all my coaches were really good.

"Stuart Raper gave me belief in myself, Chris Anderson taught me how to play tough and be tough, John Lang gave me my first opportunity, Ricky Stuart taught me how to go to that next level and be the player people want to play with, and Shane Flanagan polished me up and turned me into a really good leader. Obviously, John Morris has been good too."

Both Stuart, the Raiders coach, and Flanagan, who is serving an indefinite ban from coaching in the NRL, will be at Gallen's farewell home match, along with 17,500 Sharks fans after the game was officially declared a sell-out on Tuesday.

"This has been my second home for 20 years, I have probably spent more time here than I have at home so it is going to be pretty emotional, but I just want to win the game," Gallen said.

While Gallen has business interests and a media career with Channel 9, he hopes to remain involved with Cronulla after hanging up the boots when their season ends.

Sharks veteran Paul Gallen.
Sharks veteran Paul Gallen. ©Paul Barkley/NRL Photos

After 20 years with the club, Gallen believes he would have plenty to offer in an off-field role.

"I look at the powerhouses of the competition, Melbourne, the Cowboys, the Bulldogs, the Roosters … they have their legends stick around," Gallen said.

"To have those guys help the young players coming through and just mentor them a little bit, to teach them about the game, I think it is really important but it is something this club has never done.

"I signed at this club in 1999 because they were minor premiers, and ET, Jason Stevens, Mat Rogers and all those guys, they just finished and they would go. I'm the sole survivor from 1999.

"I don't know if they tried to stick around or what the go has been but they just never have and that is something that I want to change and help the place keep growing."