The Newcastle Herald revealed last month Nikita Tszyu, the younger brother of Tim and son of Kosta, would be part of the event, but No Limit Boxing announced the card's date, along with Gallen's inclusion, at a Sydney fight night it held on Wednesday night.

That card was headlined by Harry Garside, who was competing for the Australian lightweight title and, according to No Limit's Matt Rose, is also a chance to feature in Newcastle.

Rose believes the Newcastle event, boosted by the addition of Cronulla Sharks legend Gallen, will attract just as much attention as Tim Tszyu's previous fights in the city.

"We can't wait to take Nikita and Gal up to Newcastle - it's going to be a huge night up there," Rose told the Newcastle Herald.

"The atmosphere up there for Tim's fights was as good as I've ever witnessed anywhere and now Nikita's got this big buzz around him as well so I'm sure he is going to be a real hit up at the 'Tszyu-castle'.

"Throw a cross-over sport legend like Gallen into the mix and I reckon we can sell out the joint."

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Gallen, who last fought in December against ex-NRL player Darcy Lussick - winning by TKO - is set to fight Australian heavyweight Kris Terzievski in Newcastle.

Gallen has made a successful transition from rugby league to boxing, holding a record of 12 wins, one draw and one loss.

Terzievski (10-1-1) fought in early March, defeating Waikato Falefehi.

Nikita Tszyu announced his arrival on the professional boxing scene with a second-round knockout win on debut over Aaron Stahl in Brisbane last month.

A different style of fighter to brother Tim, the 24-year-old has been dubbed "The Butcher".

Garside, who claimed a bronze medal at the Tokyo Olympics, won his professional debut on the night Gallen fought Lussick in a fight that lasted less than three minutes.