Wayne Rooney believes Lionel Messi's arrival in the MLS will bolster the league on and off the pitch but he delivered a warning to the Argentina superstar.
Messi's arrival at David Beckham-owned Inter Miami is imminent with the club and league pushing the boat out to secure his signature. Rooney, manager of DC United, questioned how Miami have pulled off the transfer coup in a dig at the Herons but has no doubt about the benefits the 36-year-old's arrival will bring.
Rooney moved from a top European league to the MLS towards the end of his career and says Messi will need to adapt to his latest challenge.
"I think the league has been growing and Messi coming over is huge news," said Rooney. "I am sure you will see a lot of different players coming over."
ALSO READ: Rooney confirms stance on signing former United star Jesse Lingard
He added: "I am a bit puzzled how Miami have managed to do it as I thought they were under an embargo. But it is great and I am sure everyone is excited to see him here.
"But it is not going to be easy for him, the league is difficult and I don't think he will come over here and tear it up immediately because the league is different and it won't be an easy ride for him."
The former Manchester United man feels Messi's move could well inspire others to join the MLS and believes his arrival proves the pull to play in the States, both on and off the pitch.
"In my view he is the best player to ever play the game," said Rooney. "The fanbase around him will be huge, commercially for the league I am sure it will be huge as well so it is massive for MLS.
"We are seeing it with [Cristiano] Ronaldo going to Saudi Arabia, that opened the door for [Karim] Benzema. With Messi coming over here it will do that again, and it shows the MLS can compete. Financially, the money in Saudi Arabia is huge but it shows that the MLS can compete with the leagues that are trying to grow in the world of football, which is a positive. It is a league where players want to come and play and it is another huge step.
"Over the years we have all seen the impact of Beckham, Zlatan [Ibrahimovic] and different players from overseas. To get Messi in the league, arguably the greatest player of all time, and still, albeit a little bit older, but he's recently won the World Cup almost single-handedly."