The 19-year-old says the time the team has spent together in recent days will be vital come Saturday afternoon.
"Brisbane was really important in terms of acclimatising to the conditions we're going to face here, as well as just getting time on the training pitch with all the team and into the style of play that we're looking to implement," he says.
"I think it has given us a lot of confidence going forwards."
With a versatile set of defenders at his disposal, All Whites coach Anthony Hudson can choose from a range of options to combat the threat of Fiji, whose danger man is undoubtedly skipper and Wellington Phoenix star Krishna.
Despite his tender years, Brotherton is very much in the mix and would relish every minute he spends on the pitch.
"I just want to put my best foot forward in training every day and, if I do get a chance to perform, I really want to help the defensive unit. Hopefully, we can keep some clean sheets," he says.
At well over six foot, the former Western Springs player is ideally built to be a centre back but is aware that genetics are far from enough to achieve his goals.
"I'm always looking to improve in all areas and I feel like I've come on in the last six months. I've been working really hard in the States to improve my athleticism, footwork and range of passing - I feel like it's been paying off," he says.
That hard graft has taken place at Wisconsin University, where Brotherton says he is now well settled.
"There's a few cultural differences and I get teased for my accent a little bit," he says with a laugh.
"But it's still a western culture so is not too different from what I'm used to. When I first moved over there were a few difficulties in getting some everyday things sorted but I've settled in pretty well now so it's all good."
The only downside is being so far away from friends and family, who will be Brotherton's first port of call once the Nations Cup wraps up.
"It can be tough at times, especially when things aren't going your way. Of course, I miss my family and friends and I'm looking forward to getting home for a few days after the tournament and seeing them all."
The best souvenir from his visit to Port Moresby would be a Nations Cup winner's medal and the quest to earn one begins on Saturday with the clash against Fiji.
The opening fixture of the tournament, the Group B game takes place at Sir John Guise Stadium in Port Moresby at 4pm local time and will be screened LIVE on SKY Sport Pop-up Channel 056 from 5.50pm (NZT).
