Louis Rees-Zammit, the former Wales rugby star, made his first appearance for the Kansas City Chiefs in a pre-season friendly on Saturday.

The ex-Wales winger made international headlines when he quit rugby to pursue a new career in American football in January.

He had been one of Wales’ star players, scoring 14 tries at international level, before making the “painstaking” decision to join the NFL’s international player pathway (IPP).

The gamble paid off when he secured a three-year deal with reigning Super Bowl champions the Chiefs in March.

But despite his contract, Rees-Zammit has no guarantee of a space on the Chiefs’ final roster, which will be announced at the end of August.

He said making his debut for the Chiefs on Saturday against Jacksonville Jaguars was a “great first experience”.

“I loved it, I loved getting the snaps I did, on special teams as well, which was great,” Rees-Zammit said afterwards.

“I’ve just got to look back on this, review it and see how I can get better.

In a post on Instagram – in which Rees-Zammit could be seen smiling with his parents and brother behind him in the stands – he said: “Time to learn from every moment and get better.”

Rees-Zammit was born in 2001 and grew up in the seaside town of Penarth, in Vale of Glamorgan, south Wales.

As a child, his parents said he was “always on the go”.

“[He had] ants in his pants,” his mum, Maxine, previously told the BBC. “His legs were moving all the time.”

“I think it was his first sports day, and he pretty much won everything,” said his father, Joe.

He first got involved in rugby at the age of seven, before deciding to pursue a career in the sport.

In 2020, aged 18, he signed his first professional contract with Gloucester Rugby.

He broke records at the club, becoming their youngest European player, before getting the call to play for Wales in the 2020 Six Nations.

His rugby career continued to sky-rocket, as he became one of the youngest players to be called up for the British and Irish Lions in 2021, and made Wales’ Rugby World Cup squad in 2023.

He has described himself as being very close to his family and, as of last year, was still living at home with his parents.

“My family haven’t missed a game, probably since I was seven,” he said previously.

“It’s the reason why I play the game, to try to make them proud.”

Rees-Zammit hinted at his future ambitions in a BBC documentary which aired last September.

“Rugby’s been amazing to me, and it’s given me everything I ever wanted. But I want more than that. I want more than rugby,” he said.

In preparation for the 2023 Rugby World Cup, he travelled to the US city of Atlanta where he worked with Chip Smith, a performance coach who trains pro-athletes – including thousands of NFL players.

Months later, in January 2024, he said that after “careful consideration” he would be joining the NFL’s IPP, a 10-week crash course designed to teach the skills to succeed in the league.

“I would like to reiterate that this does not necessarily mean I am retiring from rugby,” he said at the time.

“But rather at this age and stage of my life, I am excited to explore a unique challenge that has the potential to diversify my skill set,” he added.

He drew interest from several NFL franchises, including New York Jets and Cleveland Browns, before signing a three-year deal with the Chiefs in March.

“Growing up in Wales, rugby is absolutely massive, so that’s what I decided to pursue. But I always had it in the back of my head that I wanted to play in the NFL one day,” he later told Men’s Health.

Before NFL rosters are cut to 53 players, every team in the NFL plays a series of pre-season games, where fringe players are given a chance to shine.

The first, when Rees-Zammit made his debut, was on Saturday when the Chiefs were defeated by the Jacksonville Jaguars in Jacksonville, Florida.

There are two further pre-season games on 17 August and 22 August, when the Chiefs will play the Detroit Lions and Chicago Bears respectively.

It is believed that Rees-Zammit could make an appearance at the next two games.

Nicknamed “Rees Lightning” because of his pace, Rees-Zammit’s progress has been the subject of much comment and debate since he joined the team.

At his debut game for the Chiefs on Saturday, he was listed as the team’s fifth-choice running back on the franchise’s initial depth chart.

The assistant head coach for the Chiefs, Dave Toub, reportedly told journalists last week: “For me, he’s doing great.”

US sports journalist Nick Jacobs said he felt Rees-Zammit had “a way to go” after observing him at a recent Chiefs training camp.

“Him being able to read it right now, that is a struggle for him,” Jacobs told the ChiefsDigest podcast on 29 July.

“I’m not saying he ca’’t get better in pre-season, I want to make that clear,” he added.

“It doesn’t mean that he’s not going to be a much better player by the end of this, because he picks things up pretty quickly from the softball game we saw, so I’m not counting him out.”

Should Rees-Zammit impress during the pre-season games, he would not be the first former rugby star to do so.

In 2019, former England rugby union wing Christian Wade scored a 65-yard touchdown with his first touch on his debut for the Buffalo Bills at a pre-season game.

But despite that, Wade never played in the regular season for Buffalo and instead spent three years on the franchise’s practice squad.

Wade previously warned Rees-Zammit to expect some “lonely” times in the NFL.

The Chiefs’ final 53-man roster will be announced on 27 August.

Perhaps the best known NFL player in the world is Travis Kelce, a tight-end for the Chiefs.

Kelce, who is the boyfriend of Taylor Swift, has won three Super Bowls with the team since being selected in 2013.

Meanwhile, fellow Chiefs player Patrick Mahomes is considered to be one of the best quarterbacks American football has ever seen.

The 28-year-old signed a 10-year contract with the Chiefs in 2020, reportedly worth $450m (£353m).