Controversial former Newcastle Knight Jarrod Mullen hasn't ruled out a return to the NRL.

Despite not playing an NRL game for almost five years, and now being 34 years of age, Mullen, who was suspended for four years at the end of the 2016 season for testing positive to a banned substance, wants to play NRL again.

His suspension was expected into 2021 following a recreational drug conviction, however, with his band expiring soon and having played for the Sunshine Coast Falcons in the Queensland Cup this season, the half hasn't given up on the idea of finishing his career.

He told The Newcastle Herald that he will re-apply to the NRL soon.

"I'm going to re-apply to play in the NRL soon and we'll see what happens," he said. "I think it should end in November and if anyone out there is interested, I'll be able to go from there.

"I've trained by backside off to try and get back in the NRL and that's still the goal. I was actually in Adam O'Brien's ear last night (at the club awards night) telling him I was ready to go and if he needs a left-footed half as a back up, I'm there.

"Pearcey got wind of it too and came up and we had a chat. He said we'd make the oldest halves pairing in history of the game.

SYDNEY, AUSTRALIA - AUGUST 24: Mitchell Pearce of the Knights looks on after another Tigers try during the round 23 NRL match between the Wests Tigers and the Newcastle Knights at Campbelltown Stadium on August 24, 2019 in Sydney, Australia. (Photo by Matt Blyth/Getty Images)

It comes after the former club captain was awarded life membership at the Knights' end of season award night.

Despite the problems the last five years have brought, Mullen was one of the best halves in the game during his time, playing 211 games for the Knights across an 11-year span.

He also represented the New South Wales Blues once in 2007, and played in the Country Origin team on four occasions between 2009 and 2014.

While most clubs are approaching the end of their roster builds for 2022, Mullen could still bring experience to any club who wanted to take a cut-price gamble on the former star.

A veteran of five finals campaigns, including a preliminary final in 2013 under Wayne Bennett, Mullen has played four Queensland Cup games this year, although only started in one. In limited minutes, he has made seven tackle busts and kicked solidly in his final game against the Redcliffe Dolphins.