GOLD COAST, AUSTRALIA - MARCH 06: Jarrod Mullen of the Knights passes the ball during the round one NRL match between the Gold Coast Titans and the Newcastle Knights at Cbus Super Stadium on March 6, 2016 on the Gold Coast, Australia. (Photo by Matt Roberts/Getty Images)

Former Newcastle Knights' star Jarrod Mullen has been cleared by the NRL integrity unit to return to the NRL.

Now the battle is finding a club.

It has been almost five years ago since a positive drug test brought Mullen's career to the ground. Having served a four-year WADA ban, and having returned to rugby league this year through the Queensland Cup, the process of reaching out to NRL clubs has now begun, according to The Newcastle Herald.

The test was originally returned positive for an anabolic steroid in the pre-season for 2017. He was provisionally suspended on January 17, 2017 by the NRL before the WADA ban was served.

He had to prove to the integrity unit he was fit to return to the NRL following the completion of that ban however, having only narrowly escaped a prison sentence in 2019 for supplying a prohibited substance, instead serving a two-year community corrections order and 300 hours of community service.

But with that in the rear-view mirror and a successful return to a team environment at the Sunshine Coast Falcons which was closely monitored by the NRL, he now has permission to land an NRL deal.

Mullen only managed a handful of games for the Falcons however in between injuries.

He hasn't played at the top level since the 2016 season, but the former one-time State of Origin representative with 211 NRL games under his belt would bring a wealth of experience.

The 34-year-old's manager told the publication he has reached out to all 16 clubs.

"I've written to every club, so they all know he's available," Steve Gillis said.

"So now it's just waiting to see if anyone will take him. I only wrote to them last night, so it's probably a bit early to be saying who's who in the zoo."

Mullen said he believes he has at least one good year left in him however.

"How long is a piece of string? The way the body feels, I reckon I've got at least one more good year in me, maybe two or three," Mullen told the publication.

"Cameron Smith played until he was 37. I'm only 34, so we'll see how we go."

As yet, there has been no speculation surrounding any clubs who may be interested in Mullen, however, he could easily slot into a similar role played by Benji Marshall at the South Sydney Rabbitohs this season.

It's unclear if his former club the Knights could use him, given Mitchell Pearce and Jake Clifford are at the club, as well as young guns Tex Hoy and Nathanael Sasagi who are both struggling for first-grade time.

Other options needing an experienced option in the halves for both the training paddock and a potential spot on the bench could include the likes of the North Queensland Cowboys, Gold Coast Titans, Canterbury Bulldogs or even Canberra Raiders.