(CNN) They are the undisputed heavyweight stars of European soccer, with seven World Footballer of the Year titles between them.

But Lionel Messi and Cristiano Ronaldo are being seriously encouraged by the current crop of high-profile MLS stars -- including Frank Lampard, Kaka, Steven Gerrard and Clint Dempsey -- to think about moving to the U.S.

"I think that's a real possibility," Lampard, the former Chelsea and England midfielder who now plays for New York City FC, told CNN Sport.

"I think they'll want to, and I think they'll be embraced if they came here. Cristiano, particularly, I could see playing in America.

"I think the lifestyle would suit him -- he's a showman and a great player."

Made for Hollywood?

Showman is right: Ronaldo's superstar status and marketable personality are tailor-made for Hollywood.

The Portuguese is the world's second most expensive player, with Real Madrid having splashed out a whopping $115 million to sign him from English Premier League club Manchester United in 2009.

Ronaldo is a limelight-loving extrovert who often appears disgusted if his teammates don't pass to him, and he has previous with Tinseltown.

Real are frequent pre-season visitors to the U.S., and Ronaldo has been romantically linked with two of Hollywood's most famous inhabitants -- Paris Hilton and Kim Kardashian.

At 31, the Portuguese star is close to entering the twilight phase of his career and he has won all there is to win at club level.

Once teammates, now opponents. Always legends pic.twitter.com/L0fiSZgsRj — New York City FC (@NYCFC) February 17, 2016

He has also hinted that he'd be keen to finish his career stateside, telling the MLS website in 2012: "This country is brilliant. The mentality of the people, the conditions, they're in the right place.

"And I think the soccer here, they do the best they can -- it's good, but I think it can be better. I hope to come here to play one day."

A 'retirement home' no more

MLS has long had to face accusations that it is nothing more than a lucrative retirement home for players who are past their prime.

But those naysayers have become quieter in recent years, with a clear spike in the league's quality evident to those who watch and play in it.

Lampard and another former English Premier League star, Steven Gerrard, say MLS is as demanding as they anticipated.

Former Liverpool and England captain Gerrard told CNN that any players thinking they could head to the States and put their feet up would be in for a "very big shock."

He also pointed to the fact that Mexico's Giovani Dos Santos, one of the Galaxy's star players and a former Barcelona and Spurs striker, had opted to join MLS at 26, in his peak years.

On the potential for Messi and Ronaldo to head Stateside, Gerrard said: "I hope so. I'd certainly recommend it, not just to those two but to players around the world.

"I'm sure they'll enjoy the life on and off the pitch because America's a super country to come and work in and enjoy.

"I know from playing with players in the English dressing rooms at home that everybody is talking about MLS now.

"Maybe five or 10 years ago it wasn't on the radar so much -- but it is now, and I'm talking about big players."

The magic of Messi

They don't come bigger than Ronaldo and Messi.

The latter is regarded by many as an all-time football genius. While not as powerful in the air as Ronaldo, he is just as prolific in front of goal and has mesmerizing close control.

Muchas gracias al fenómeno @stephencurry30 por mandarme su camiseta firmada con el número 30 para felicitarme por los 30 millones en Insta. ¡ cuando llegues a 10 millones te mando la mía! 😜👍🏻 // Thanks so much to the great Stephen Curry for sending me a signed jersey to congratulate me for reaching 30 million followers on Instagram. As soon as you get 10M I'll send you mine! 😜👍🏻 A photo posted by Leo Messi (@leomessi) on Dec 4, 2015 at 7:02am PST

He's scored an astonishing 301 goals in 335 league games for Barcelona and has won seven La Liga titles as well as four Champions League crowns -- double Ronaldo's tally.

There's no hint of Messi leaving Spain any time soon, but Brazilian Kaka, another of the jewels in the MLS crown, thinks both the Argentine and Ronaldo will end up in the States.

"I think one day, probably, they're going to come to join MLS," the 2002 World Cup winner told CNN. "I know that depends on a lot of things.

"But both already said that they wanted to play here, they like the possibility to live in America. So probably one day we will have the joy of seeing these guys playing here."

Beckham: The Game changer

The arrival of David Beckham in 2007 was a pivotal moment in MLS history.

The darling of English football and a recognizable face the world over, his five-year contract with LA Galaxy was seen as a game-changer for the league.

That deal is also helping to play a part in the MLS expansion, with the former Real Madrid and Manchester United star exercising his option to own a franchise at a discounted fee.

Miami is one of four new teams scheduled to join the league -- Minnesota and Atlanta in 2017, another LA team in 2018, and Beckham's outfit in 2020.

More teams means more competition, on and off the pitch, and more scope for better players to make the transition.

'The sky is the limit'

Clint Dempsey, who began his career with New England Revolution before a successful six-year stint in the EPL with Fulham and Spurs, thinks the "sky is the limit" for MLS.

"It's only going to continue to grow," the Seattle Sounders star told CNN.

"More money's going be involved with it. The quality of players is going continue to increase. Competition is just going to get better and better.

"As long as you can keep on track and keep everything in order, I think there's no reason why the game shouldn't continue to grow with what we've seen in recent years."

Ready for March 6th ✔️

Ready for tifo ✔️ https://t.co/11KZ29z9fF — Major League Soccer (@MLS) February 17, 2016

David Villa was in the same team as Messi at Barcelona, and was part of the all-conquering Spain side that won the 2008 European Championships -- its first since 1964 -- before landing a maiden World Cup triumph in 2010.

Now playing alongside Lampard and former Italy, Juventus and AC Milan star Andrea Pirlo for New York City FC, Villa agrees with the rest when asked about the potential arrival of Messi and Ronaldo.

"I hope both of them may be here," he said. "Obviously they are both two of the greatest players of today and in the history of football.

"The MLS is making a better impression on European soccer players, and many of them want to be here -- and that will improve the league a lot."

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