Jamayne Isaako has been backed by Broncos coach Anthony Seibold to fire at fullback as utility back Herbie Farnworth gets his chance on the bench in Friday night’s clash with the Cowboys.

Brisbane arrived in Townsville on Thursday to train at the new Queensland Country Bank Stadium ahead of the historic showdown.

Isaako gets his opportunity to start after the devastating ACL tear suffered by Jack Bird at training on Wednesday.

Isaako trained at fullback all pre-season and was edged out by Bird after the 2016 premiership winner shone at training and in the trials.

While Isaako has played most of his NRL career on the wing he did have a full year at No.1 in 2017 for the Souths-Logan Magpies, the same season he was Intrust Super Cup fullback of the year.

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The Kiwi international is now set for an extended run in the position and has the full backing of his coach.

"He has trained the whole pre-season there and in both trial games he played at least half a game at fullback, so it is not a big shift for us," Seibold said after arriving in Townsville on Thursday.

"We are devastated for Birdy, we really are. The way he applied himself to pre-season was just incredible but all we can do now is prepare ourselves for our next job.

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"Jamayne has got an opportunity and sometimes it is not how you get your opportunity but what you do once you are there.

"He is a fantastic attacking player and we just want him to improve a few areas of his defence but he knows that, and he will certainly get better the more he plays fullback.

"Jamayne has played for New Zealand for a couple of years so we are bringing in a real quality player."

Farnworth played two NRL games last year on the wing where he impressed in both outings, including a gritty display in the 18-all draw with the Warriors where his penchant for taking the tough carries came to the fore.

A former soccer prodigy in the Manchester United junior system, the 20-year-old flyer covers wing, centre and fullback and will give Seibold plenty of options if an outside back is injured.

"I’m a really big fan of Herbie with regards to how he prepares himself and what he did last year in the Queensland Cup where he was really consistent for Norths Devils," Seibold said.

"He is ready to play. He was unlucky not to be in the original 17 so I think for him to come on the bench is a reward for a great pre-season, and season last year.

"How much time he plays and what position he plays will be guided by where the game takes us but Herbie gives us great utility value off the bench."