There's testing out an injury, and then there's breakdancing in front of thousands of people in Las Vegas to prove your hamstring isn't sore.

Penrith superstar Brian To'o busted out a backflip as part of a hip-hop dance routine for the crowd at the NRL's official fan event on Thursday (Friday AEDT).

Punters from Australia, England, New Zealand, the US and beyond lined Fremont Street to officially welcome each of the eight teams to the stage ahead of Sunday's games (AEDT).

With music pumping, punters cheering and Cronulla players throwing footballs into the crowd, Warriors coach Andrew Webster declared "the NRL has taken over Las Vegas" with its festivities.

Amid the excitement, the two on-stage emcees challenged each team to nominate their best dancer to hype up the crowd, with the Jillaroos' Sarah Togatuki and Sharks stars Braydon Trindall and Will Kennedy particularly impressive.

The Panthers' performance staff must have had their hearts in their mouths when four-time premiership winner To'o showcased his moves.

At pre-season training, To'o strained his hamstring seriously enough to miss the clash with Cronulla at Allegiant Stadium, but said he simply could not resist a dance.

"I had to represent the brothers so that just pretty much came out," he said on the red carpet.

Penrith are beginning life without Jarome Luai, James Fisher-Harris and Sunia Turuva in round one and an injury to superstar To'o loomed as yet another blow.

Prized for both his power out of yardage and finesse at the tryline, To'o showcases the winger's importance in the modern game better than any other NRL player.

But the Samoan international said his dance moves doubled as a test for his hamstring and was confident he would be back on the field "very soon".

"(It was) a bit of a test and it looks pretty good," To'o said.

In his absence, second-rower Luke Garner joins the centres to face the Sharks and Paul Alamoti starts on the wing.

But attention is likely to be fixed more closely on inexperienced Casey McLean, who slots onto the opposite wing to replace Wests Tigers recruit Turuva.

McLean, 18, looks set to become the youngest staple of the Panthers' starting line-up since their premiership dominance began in the 2020 season.

But the teenager flaunted his ability with four tries for New Zealand on Test debut against Papua New Guinea last year, and has made seven NRL appearances for Penrith already.

"He's got a big future ahead of him," To'o said of McLean.

"He pretty much showcased his skills last year. There's a reason why he's in the team. I can't wait for him."

To'o will be an enthusiastic supporter from the sidelines at Allegiant Stadium.

"I'm obviously gutted that I can't play but I'm super excited to see the boys do their thing," he said.