The Broncos are in talks to extend the contract of promising teenager Herbie Farnworth as they move to sure-up their outside back stocks long term.

Farnworth can play fullback, wing or centre and impressed in two NRL games for Brisbane this year - a 24-22 win over the Sharks and an 18-all draw with the Warriors. Against the Warriors he showed plenty of physical toughness and endurance out of his own end, making 144 metres from 19 runs.

The 19-year-old is on contract until the end of 2020 and the Broncos are keen to extend his stay for a further two seasons. There is interest from other clubs in the England-born Farnworth, who is also a talented soccer player formerly in the Manchester United junior system.

Farnworth enjoyed a stellar season in the Intrust Super Cup for Norths Devils, scoring 204 points from 20 tries and 62 goals in 16 games.

He has a robust and athletic frame - he is 190cm and weighs 94kg - and is highly regarded at the Broncos for his work ethic and mental strength.

The Broncos have already extended 18-year-old outside back Xavier Coates’ deal until the end of 2021 after he impressed in three top grade games for the club this year.

Broncos' top five tries of 2019

Former Queensland Reds flyer Izaia Perese, who played two Telstra Premiership games off the bench, is on the books until the end of 2020.

Darren Lockyer, on the club’s retention and recruitment committee, said recently that the Broncos also want to keep centre Kotoni Staggs long-term with the robust centre already secured until the end of next season.

Staggs can negotiate with other clubs from November 1 but the Wellington product is now the first picked for the Broncos in the centres after a stellar 2019 season.  

Former Brisbane centre and NRL.com columnist Steve Renouf said the club needed to have competition for spots in the outside backs and has been impressed with the development of Farnworth, Coates and Perese.

"Herbie Farnworth is maturing into a really good player," Renouf said.

"He is physically and mentally tough, he’s quick and he has a good work rate. I like the way he goes looking for the ball and he showed against the Warriors that he doesn’t mind the contact.

"Coates and Perese have done well each time they have played so it is promising that we seem to have good depth in the outside backs, and you need that competition for spots.

"When I was coming through the Broncos had Chris Johns and Rohan Teevan and then they signed Dale Shearer, Tony Currie and Peter Jackson so I had to play my best footy to get into the team."