The worst place in the United States for football. The biggest challenge in sport.

Those were the reactions from two high-profile figures in US football to David Beckham's widely anticipated announcement on Wednesday that he is to build a club from scratch in Miami.

The former Manchester United and England player, together with an investment group that could yet include Miami Heat basketball icon LeBron James, is forking out a reported US$25 million for the ambitious Major League Soccer franchise.

Beckham, 38, who retired last year after a career that also took him to Real Madrid, LA Galaxy and Paris Saint-Germain, is banking on his star pulling power and growing prominence in the US to create what he called a "global" team that can attract the best players in the world.

The MLS is hoping the ex-England captain and his new team -- which is not expected to be playing until 2017 at the earliest -- can increase the appetite for soccer in a country that still finds the "beautiful game" something of a turnoff.

Beckham told a press conference that he was under no illusions as to the scale of the task in an area that has already claimed two football clubs as victims: Miami Fusion and Fort Lauderdale Strikers.

"He's picked the worst possible city for this franchise," said Rodney Marsh, a former Manchester City striker who finished his career and managed in the US in the 1970s-80s.

Marsh, who is still heavily involved in United States football, said the Fusion struggled to get enough fans through the gates, despite signing renowned Colombian Carlos Valderrama to attract Miami's large Hispanic community.

Hemorrhaging money, the Fusion folded more than a decade ago, leaving Miami without a top-level football team.

Marsh said: "It's a lot more than David Beckham coming in, getting a few players and throwing them together. I hope it's going to work. But it's going to take a lot more work than even David thinks.

"I'm sure he'll attract a lot of people, but people don't come to watch the owner. They come to watch the players. It doesn't matter that David Beckham is the owner."

Marsh told the London-based talkSPORT radio station that he does not believe that football is any more popular in the US than it was 30 years ago and says Miami will be particularly hard to crack because it has so many professional sports teams already.

Ray Hudson knows better than anyone what will happen if Beckham's as-yet-unnamed team fails to spark the Miami public's interest beyond an eye-catching press conference at a downtown art museum.

The Englishman was manager of the Fusion shortly before it was dissolved.

"It's the biggest challenge in sports I can imagine," Hudson said.

"With the history of sports in this area, it's sufficient to put anyone off. The bling of Beckham is not going to be enough. It's not going to be," he told reporters, nevertheless giving the initiative "an absolute fair chance to rise above and succeed" because of Beckham's name.

"I think this community now is so ready and when they look at how MLS has succeeded in other marketplaces they'll want to have that gameday event and gameday experience. We're watching PSG, Real Madrid and Barcelona (on television) and it's fantastic, but it isn't the smell of the stadium -- and people miss that," he told the official MLS website.

Many experts believe that Miami's Hispanic or Latino residents -- about two-thirds of the city's population -- hold the key, although prominent among them are Cubans, who traditionally go in for baseball and not football.

Recent exhibition matches in Miami involving international teams have drawn crowds of 67,000 and 71,000.

The Miami-Fort Lauderdale region was also the highest-rated television market in the United States for the 2010 World Cup.

"I know this city is ready for football, soccer, this time around," Beckham said, without expanding on the theme.

Critics said his announcement was big on show but lacked specifics: as well as no team name, there is no confirmed site yet for a stadium.

Asked in Spanish -- translated into English -- if he had a vision for getting Miami's diverse range of residents behind his pet project, Beckham said: "Umm, my plan?

"We will want to bring some of the best players in football to Miami to play in this team. I've seen what happens to teams when you bring great players in -- I'm talking about the Heat.

"When you look at a team like that, a franchise like that, you want success and you want people talking about the team. And yes, we will bring great players into this team."

He added: "But one thing that I want to achieve more than anything, I want to set up a great academy -- a kids' academy -- an academy that brings through young players from all over Miami.

"We want local talent, local children and local players that believe they can play in the MLS, in the American team, the Mexican team, or wherever they're from."