Kangaroos winger Dane Gagai admits to being “blown away” by the athleticism, size and power of the Fijian side and is expecting an explosive start to the World Cup semi-final in Brisbane on Friday night.

The qualities of the Bati are epitomised by Melbourne winger Suliasi Vunivalu. The nimble giant has scored eight tries during the tournament after having turned in a stellar NRL season for the Storm.

Gagai pointed right across the park to the dangers Fiji would pose as they target a second upset in as many weeks. From Kevin Naiqama at fullback, to Jarryd Hayne at five-eighth and giant Viliame Kikau in the back-row, Gagai said they were “a great outfit”.

“We know we are coming up against a very confident, passionate and athletic side,” he said.

“They have some great individual players and if they all come together as one it is going to be a nice battle.

“Vunivalu … is an outstanding athlete. He has the physical makeup and the attitude to go with it, because from what I hear he works hard. He’s aggressive, a big human and has that X-factor that most Fijians have where they can create something from nothing.

“To see blokes that big move as fast as they do and be as agile as they are, that’s what blows my mind.

“That goes across the board. So we can’t just watch out for one because they have a lot of players who can strike from nowhere.

“The first [international] game I played against England was up there with the toughest games I have played and I am expecting an explosive start against Fiji.”

Gagai, who will play for South Sydney in the 2018 NRL season, is making the most of his first World Cup campaign.

Speaking at Kangaroos training on Tuesday, the 2017 Wally Lewis Medal winner described how Wayne Bennett had helped resuscitate his career at the Knights after he was let go from the Broncos by taking a keen interest in him as a person and not just a player.

It is why he also thrives under the coaching of Mal Meninga in the Australia setup.

“That is something Mal does too. He looks after you as a person and not just as a player who he tries to get wins from every week,” Gagai said.

“To be able to play underneath Mal is something I have really cherished because he has helped my career out a long way too.

“He brought me into the Origin squad in 2015 and [on debut] I wasn’t nervous because of the belief he had in me.”

Meanwhile, Gagai said he was looking forward to playing alongside a fit and firing Greg Inglis at the Rabbitohs.

“It is going to be a bit more fun playing alongside him rather than tackling him,” he grinned.

“He is one of those athletes who is competitive and aggressive. He had this year off and I am sure he will do everything to get back out on the field and bring success to the club.

“They have Sam Burgess in the middle, Angus Crichton had an outstanding season and even the young outside backs. There are a lot of things I liked about it.”

New South Sydney coach Anthony Seibold is also someone he knows well.

“He was the assistant [Maroons coach] in Origin and I spent a bit of time doing video with him. We have a good relationship,” Gagai said.

While relishing the prospect of joining the Rabbitohs next year, Gagai said he “enjoyed every second’’ of his time at the Knights.

“This year we were going for our third wooden spoon and we had 13,000 people turn up to the game. The passion of the Novocastrians, I have never seen nothing like it,” he said.

“They are a young team and have made a few good buys this year. They are a team on the way up. Each one of those players I played alongside gave 100 per cent each week and that is all you can ask of somebody.”

Australia have named an unchanged side to face Fiji at Suncorp Stadium.