Why Lionel Messi is the most marketable athlete in the world - after beating LeBron James, Alex Morgan, Lewis Hamilton and more

Long said: “There's that courtside culture, that sports and entertainment culture that we see in the NBA and the NFL, more so than anywhere else. And I think he's [Messi] rubbing shoulders now with not only [David] Beckham and other past and present greats of football, but all these other cultural icons in the sports and the entertainment world.

"That kind of moves him into a different dimension almost, I think, that we haven't really seen around Messi and certainly didn't see when he was at Barcelona so much. But I think he has the potential to have a Beckham-like impact, commercial impact on MLS, however long he sticks around in the league, building up to the next World Cup for sure, which could ultimately be a swansong.

"It's a really interesting dynamic to see Messi in America. A match made in marketing heaven.”

Messi doesn't top the 50MM list because LeBron James turns up at Messi games. The list is more than a popularity contest and ranks athletes across several metrics.

Part of the reason for Messi coming top is down to his pubic support of causes and charities, factors growing in importance in sports marketing.

Long added: "From an economic perspective, his market value and estimated worth rank him very highly. But also his public support for environmental and social causes that he's not necessarily well known for. [He's a] UNICEF ambassador, he's got the Leo Messi Foundation, he supports other environmental initiatives and things like that. So that's worked in his favour.

"That kind of cause element is really important for brands these days, I think, when they're aligning with athletes."