Petaia left the Queensland Reds in 2024 to pursue a career in the NFL.
Things were looking promising when Petaia signed with the Los Angeles Chargers in April, 2025, on a three-year deal as part of the International Player Pathway.
But a lingering hamstring injury that turned out to be more serious than first thought ended up causing his downfall, with the Chargers releasing Petaia just four months later.
Petaia returned to rugby ranks - first playing in France, before recently signing with Japanese outfit Urayasu D-Rocks - and is now in Perth with the Wallabies squad ahead of Sunday's Test against South Africa at Optus Stadium.
The 26-year-old loved his time in the NFL, but said the initial diagnosis of a minor tendonitis hamstring injury actually ended up being a lot worse.
"I was kind of misdiagnosed over there," Petaia told AAP.
"I kept trying to train through it. It's hard over there when you're new to the sport and you're trying to prove yourself.
"I then ended up getting a second opinion on it. I had a hamstring tendon (issue), which was unfortunate.
"But that's sports, and then obviously signed the medical settlement and ended up coming back to Australia.
"There's no bad blood with the misdiagnosis. I think it's just unfortunate."
Petaia, who ended up needing eight to 10 weeks to recover from the injury, knew something wasn't quite right while he was suiting up for one of the pre-season games.
"It was just no good," Petaia said.
"I was warming up, and I was just like, 'I don't think it's going to be right'. And a week after that, I went back into rehab."
Petaia's go-with-the-flow mentality means that instead of dwelling on his missed chance in the NFL, he is now excited for what awaits him in rugby.
And with a home World Cup just over a year away, there's plenty to be pumped about.
For now, Petaia is more focused on learning the names of his new Wallabies teammates, given the last time he was in the Australian gold was at the 2023 World Cup.
He said he went from his rugby playing weight of 102kg up to 110kg while pursuing his NFL dream, given the need for more power and less fitness in the American sport.
Now back in rugby, Petaia said he was around the 100kg mark again and feeling fit and ready to take on the Springboks.
But the fun experiences from his time in the NFL are still very much cherished.
"It was cool catching balls from (Chargers quarterback) Justin Herbert," Petaia said.
"And lining up across guys like Derwin James was crazy stuff, and attempting to block guys like Khalil Mack - just names like that and being around the building was just an experience in itself."
