Getty ImagesSince moving to the US, Rees-Zammit missed out on selection for the Kansas City Chiefs side Former Wales rugby star Louis Rees-Zammit just needs more time after struggling to break through in American football, according to the NFL's top boss in the UK.
The 23-year-old quit rugby union earlier this year to pursue an NFL career, first with the Kansas City Chiefs and now with the Jacksonville Jaguars, but hasn't played in the league yet.
The general manager of NFL in the UK and Ireland, Henry Hodgson, tells BBC Newsbeat "no one's done" what Rees-Zammit's trying to do in such a "short space of time".
"There's a lot for him to learn," Henry says.
"His natural talent will stand him really well in the NFL but he needs to learn the nuance of the game.
"He is doing well and hopefully we'll see him if not this season, next year."
'He could set a season on fire'Even though it's been a bumpy start for Rees-Zammit, Henry hopes his transition will encourage athletes to try out for a spot in the league, rather than put them off.
"What he's doing is encouraging youngsters in this country that there is a pathway – he's just doing it in a very accelerated timeline.
"We have an NFL Academy in the UK which takes kids aged 16-18, so instead of trying to do what he's done in 10 months, we're talking about doing that over a long period of time," he says.
He points to Travis Clayton from Basingstoke, who's been signed to the Buffalo Bills after a short spell with the Academy, as someone who shows that with more time "it can be done".
Getty ImagesWales international Louis Rees-Zammit traded a successful rugby union career to pursue his NFL ambitions Rees-Zammit was one of Wales' best players, with 32 caps since making his debut in 2020 but said earlier this year he was ready for a new challenge.
He also had a successful career with Gloucester, where he played as a winger after first joining the side as a teenager.
Henry says it was "a bold step" and in August he faced a set-back when he failed to make the squad for Super Bowl winners Kansas City Chiefs, prompting his move to the Jags.
Other rugby players have tried to make the move to the NFL, with limited success.
Former gaelic footballers Charlie Smyth and Jude McAtamney, who like Rees-Zammit came through the NFL's international player pathway programme, also missed out on squad places this year.
"They are similar sports in the fact that they're contact sports but they're also very, very different," Henry says.
He hopes Rees-Zammit might break the streak and is expecting to see him play in London this week.
"It will be great for him to get some action and fingers crossed that might happen," he says.
Getty ImagesTravis Kelce's relationship with Taylor Swift sparked a "global peak" of interest in the NFL, Henry says And at Sunday's match, some fans told Newsbeat they were optimistic about Rees-Zammit's future.
"There's so many big names that flop but one good game and he could set a season on fire," says Tom, from London, who's been coming to NFL games in the capital for 10 years.
Jags fan Bernard who travelled from Florida to support his side is excited too.
"He's a good addition for us," he says. "He brings a different aspect of the sport, different techniques we can use."
The Jags are among five US teams in the UK for the 2024 NFL London Games, being held at Tottenham Hotspur Stadium.
There's one final match between New England Patriots and Jacksonville Jaguars on 20 October.
More than 60,000 fans attended each game and Henry says the sport is making an effort to grow, particularly with younger audiences.
He says there's been a "global peak of interest" in the past year since Taylor Swift confirmed her relationship with Kansas City Chiefs player Travis Kelce, which he hopes will carry over to UK fans.
"The entertainment that comes with the NFL, which includes Travis and Taylor, that is in our DNA," Henry says.
"What we have to do is then convince them the sport is awesome as well."
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