Fotu, a defensive tackle drafted in the fourth round out of Utah in April, was an accomplished rugby player in high school. He didn't make his high school football team his junior season because his focus was on rugby. He traveled the world as part of the USA Rugby Boys High School All-American team.
But, like many other multisport athletes in high school, he faced a decision: Should he continue with rugby or pursue football? He picked football.
Five years later, he doesn’t regret giving up his rugby career, even if it meant possibly passing up a chance to play professionally or for the U.S. national team.
"Once I made my transition back to football, there wasn't really any regret for it," Fotu said. "I feel like I've done better at this sport, just not knowing what could have happened.
"But, for me, I believe that everything happens for a reason."
Fotu's foray into rugby was a family affair. His two older brothers, Joe and Anthony, who both played college football, played for the USA Rugby Boys High School All-American team.
All three were big and athletic, said Salty Thompson, who coached the national team. Thompson first heard about Leki Fotu during his freshman year at San Leandro High School, outside Oakland, when he played for the Peninsula Green Rugby Club, based in San Francisco.
Thompson instantly liked what he saw in Fotu, who joined the national team as a sophomore.
"It was easy to take a chance on him based on his size," Thompson said.
And it only got better for Thompson, who described Fotu as "light on his feet" and said he "could move like he weighed 180 pounds," despite being in the 240-pound range. Thompson said Fotu was a balanced rugby player who could run with the ball and was a "menace" to bring down.
Fotu started playing the lock position, which is comparable to a lineman.
"He could push," Thompson said. "He's big and strong. He could jump.
"He was just a beast carrying the ball. He needed at least two defenders to get him on the floor. He didn't score a lot of spectacular tries but he did get a lot of the hard yards."
Later in high school, Fotu was moved to the 8 position, which requires pushing up front, tackling and ballhandling. It's the one position that needs a hybrid of size, power and speed, Fotu fit the profile.
Playing for the national team took Fotu around the world and lined him up against some of the best players on the planet from countries such as Argentina, France, Uruguay and Belgium.
Back home, though, his athletic career took a detour before his junior year of high school. Fotu didn't make the San Leandro football team after playing as a freshman and sophomore because his focus that summer was on rugby instead of football.
However, it opened up a once-in-a-lifetime opportunity.
Free from any football commitments, Fotu moved to London to play for the Wasps, a Premiership Rugby team. He joined their Under-18 team as a 15-year-old for three weeks in late summer 2014, said former Wasps Academy director Matt Davies, who discovered Fotu with the help of Thompson.
"Leki was a huge human even back then, but incredibly quiet," Davies told ESPN in an email. "Travelling across to the UK and diving straight into a professional rugby Academy would have been a daunting task, but he handled it brilliantly.
"He had and obviously still has phenomenal physical attributes. Great size, but his power and speed were noticeable. He enjoyed the physical side of the game and you could see that he would be able to make big impacts."
With the Wasps, Fotu faced players who are now among London's best professional and national team players.
"He showed that he wanted to learn and had a huge desire to improve," Davies said. "The standard of player is very high in English club Academies but I saw enough in Leki to believe he could have developed very well in a full-time environment.
"The raw aspect of his game was the power and pace he bought in close quarter contact, but you could also see a subtlety in regard to his ball skills that showed there was definitely potential."
Fotu returned from his time with the Wasps a better rugby player and, in turn, a better football player. Like football, rugby emphasizes leverage, vision, footwork and conditioning, said Jeff Wilson, Fotu's rugby coach at Herriman High School in Utah.
Thompson believes that trip to London could've changed the trajectory of Fotu's career had the Wasps offered him an academy contract. That would've kept Fotu in London for the next five years, setting him up for a professional career in Europe, where it's possible his salary would be in the low six figures, with the potential to earn more. His salary this season will be $610,000.
Thompson and Wilson both believe Fotu would've been a professional and a member of the U.S. national rugby team had he stuck with the sport.
Fotu's family moved to Utah midway through his junior year of high school and he enrolled at Herriman High School. There, he played rugby for two seasons and football as a senior. Wilson, who also coached football at the school for 15 years, saw Fotu's natural talent on the pitch but he knew instantly football would be his future.
"Ability-wise, he had the chance to play on Sundays," Wilson said. "So he'd be foolish, as much as -- maybe I'm an anomaly because I'm in both communities -- people in the rugby community would like him to stay with rugby, but for Leki, it was a no-brainer. Not many people get that opportunity.
After talking it over with his mother, Fotu decided that football was the better path. It led him to a college scholarship and, then, the NFL.
"It was," Fotu said, "just a better option for me to pursue this."