On his pro day, Mailata ran the 40-yard dash in 5.12 seconds and completed the short shuttle in 4.67 seconds. Those times would have put him in the top-10 for both categories had they come at the NFL Combine earlier this year.
Although not as big a name, Mailata's journey has some similarities to that of NRL star Jarryd Hayne, who quit the sport in 2014 to pursue his dream of playing in the NFL, which he did for a season with the San Francisco 49ers.
Highlights of Mailata trampling opponents playing rugby league is what attracted him to NFL teams in the first place. Although he never played first grade, he was a scary prospect in the South Sydney Rabbitohs National Youth Competition (Under-20s) team.
The NFL's official Twitter account tweeted out Mailata's highlights video — which was played at the Draft — and accompanied it with this caption: "His highlights are ... insane, dominant, ridiculous."
Michael Maguire was the senior Rabbitohs coach when Mailata was at the club and was immediately struck by his size and later, his attitude.
"I'd never seen anything like it. He was enormous: six-foot-eight and 166 kilos," Maguire wrote for Players Voice.
"As we walked towards each other, he kept getting bigger and bigger until you felt he was pretty much going to fill the entire space. I reckon he's still the largest bloke I've come across in rugby league.
"He had an incredible will to improve. He was hungry. Pretty much all our conversations centred on ways he could get better. He was a man mountain, but he wasn't going to rely on his size and talent to get him there.
"He'd actively seek out advice on what he needed to do to be successful. And then he went out and did it."
But Mailata's biggest attribute was also a curse. A full-time career as a league player was always going to be difficult because while his size allowed him to run over the top of people — it wasn't reasonable to sustain that ferocity for 80 minutes.
Aerobically it was tough to match everyone else. The explosiveness in American football suited him much more than the repeat efforts required on the rugby league field.
So his agent Chris Orr set some things in motion and Mailata impressed scouts during a week-long workout in Los Angeles — and the seed was planted.
"In that week of the workouts, I was fascinated by the sport. It gained my interest so much," Mailata said, per nfl.com.
"I was blown away by the athleticism of the players at the position they were trying me out at — offensive tackle. Naturally, I just wanted to learn more. Instinctively, I craved that training."
Mailata has spent the past month training at the IMG Academy in Florida and in March strutted his stuff in front of all 32 teams at the pro day where he dished up such impressive numbers.
He also visited eight teams, including the Eagles, and was particularly impressed with how much attention offensive line coach Jeff Stoutland paid him. It proved to be a sign of things to come as Philadelphia got its man.
"I feel like I earned a little bit of coach Stoutland's respect that day. I feel like he challenged my manhood," Mailata said after he was drafted.
Although hopeful of being drafted, a humble Mailata wasn't expecting the world. Earlier this month he admitted he had much to learn and was desperate to do so.
"I went there not really understanding the level of athleticism and skill the guys up front at the line of scrimmage had," Mailata told nfl.com. "But now having been put through the many drills and testing, it certainly opened my eyes to how good the NFL athlete is.
"I am looking forward to the challenge and feel confident I can succeed, but I now have a lot of hard work in front of me before I can start thinking of wearing an NFL jersey."
After today's announcement, wearing that NFL jersey may come sooner than he thinks.
