One Friday night, a couple of weeks ago, the family of Louis Rees-Zammit were given an early glimpse of Arrowhead Stadium in full voice.

They were exposed to the noise and the colour and the electricity that surges around the 76,000-seater home of the Kansas City Chiefs.

Pop star Morgan Wallen had launched a two-show takeover and so they strapped in for an evening of country music. It was a spectacular sight.

Wallen walked out alongside Patrick Mahomes, the quarterback who has turned the Chiefs into the NFL’s new dynasty, and Travis Kelce, the superstar tight end who has spent much of the summer following his girlfriend Taylor Swift on a worldwide tour. On Saturday it was the Welshman’s turn to join his new teammates on centre stage.

His entrance was rather more low-key — a pre-season runout against the Detroit Lions. But, for Rees-Zammit, it represented a first taste of life at his new home. Next week the 23-year-old Welshman will discover if it might also be his last.

Seven months have passed since Rees-Zammit quit rugby union to join the NFL’s International Player Pathway. He survived a three-month bootcamp and signed a three-year contract — believed to be worth £2.19 ($2.83m) — with the back-to-back Super Bowl champions. On September 5, the Chiefs begin their title defence against the Baltimore Ravens. The question is whether Rees-Zammit will be on the field or watching from afar.

It’s far from guaranteed. It’s the risk he ran. NFL teams are currently deep in training camp, when up to 91 players battle for 53 spots on the roster. It’s a cut-throat business and D-Day is looming.

‘I’m not going to be the best player in the world overnight… I’d never played this sport before one week ago,’ Rees Zammit said after facing the Lions.

‘People try and put me down... but I’m going to continue to work really hard every day and learn as much as I can.’

Nowhere blends sport and show — and scandal — quite like the NFL. Nowhere does the spotlight burn brighter than in Kansas City. Days after winning the Super Bowl, the Chiefs’ victory parade spiralled into a deadly mass shooting and the turbulence has barely relented since.

Wide receiver Rashee Rice is under investigation over a 119mph car crash involving half a dozen cars. Defensive lineman Isaiah Buggs was released — and then sentenced to a year of hard labour — following allegations of domestic abuse and animal cruelty. BJ Thompson, 25, suffered a seizure during a team meeting and went into cardiac arrest.

At Arrowhead, Wallen performed in a Chiefs jersey carrying the number of Harrison Butker, the kicker who sparked a recent backlash by suggesting one of women’s ‘most important’ roles is as a ‘homemaker’. All the while, Rees-Zammit has been trying to realise a dream.

Life was rather more serene at Gloucester, where he had cemented himself as a rising superstar of rugby. The opportunities here, though, are enormous. Provided he can make it on to the field.

Teams have until August 27 to trim the fat and, on the current pecking order of Chiefs’ running backs, Rees-Zammit sits fifth. Most rosters will include three or four. Should he miss out, the Welshman faces a year in the shadows of the practice squad. Christian Wade never played a snap in the NFL before returning to rugby from the Buffalo Bills.

Rees-Zammit, who reportedly put on more than a stone of weight over the summer, has certainly caught the eye.

‘I love him. I love the way he works,’ said assistant head coach Dave Toub. ‘The athletic ability is unreal,’ Mahomes added. NFL teams have a playbook the size of an Argos catalogue and so, typically, Rees-Zammit is in meetings until 8pm and then spends another two hours studying. That work isn’t going unnoticed.

Thanks to rugby, his versatility could prove crucial. Though Rees-Zammit is listed as a running back, his immediate future may lie on special teams — punts, kick-offs, field goals. 

On his NFL debut, against the Jacksonville Jaguars, the Welshman carried the ball, caught the ball, made a tackle and even took a kick-off. His cameo against the Lions involved taking another kick-off, returning a kick-off and operating as a wide receiver. Head coach Andy Reid has suggested Rees-Zammit’s hopes of making the 53 will likely hinge on his impact on special teams.

Thankfully he has timed this move well. A new kick-off rule — designed to incentivise players to run the ball back — has made versatile players who can kick, tackle, catch and attack open space a more valuable commodity. But still uncertainly reigns.

Midway through his pre-season debut, Rees-Zammit sat next to Kelce on the Chiefs bench.

‘What season is this for you? 13?’ he asked the tight end. ’12,’ Kelce replied. The most recent ended with a third Super Bowl and a Las Vegas afterparty alongside his significant other. ‘Not bad, eh?’ Rees-Zammit said. The clock is ticking until the Welshman’s first.

Only one more audition — against the Chicago Bears — remains for him to prove he deserves to rub shoulders with the elite. To prove he, too, can light up Arrowhead.