UEFA is not worried about more players joining the Saudi Pro League, the European football governing body's president, Aleksander Ceferin, said on Sunday.

Lionel Messi, Cristiano Ronaldo, Karim Benzema and Luka Modric have won all of the Ballon d'Or awards since 2008. Ronaldo joined Al Nassr in January; Benzema agreed to sign with Al-Ittihad in June. Both make record money in their new clubs. Saudi teams have also reached out to Messi and Modric with lucrative offers, but both rejected them.

"I think that it's mainly a mistake for Saudi Arabian football. Why is that a problem for them? Because they should invest in academies, they should bring coaches, and they should develop their own players," Ceferin said when answering a question by Dutch broadcaster NOS.

"The system of buying the players that almost ended their career is not the system that develops football," he added. "Tell me one player who is top, top age and who starts his career and went to play in Saudi Arabia?"

Ceferin has a point. Ronaldo was nearly 38 years old when he joined Al Nassr and had no major European club willing to sign him. Both Benzema and Modric are at the end of their careers as well. Messi is in a better form than the other three, but also differs widely from his prime.

Ruben Neves, 26, was acquired by Al Hilal from Wolverhampton Wanderers for 47 million pounds (about $60.2 million). 31-year-old Sadio Mane of Bayern Munich is being targeted by Saudi clubs as well, but neither him nor Neves is even close to being among the top players in Europe.

"But it's not about money only. Players want to win top competitions. And top competition is in Europe," Ceferin said. "We didn't lose them. They still play football. At the end of their career, some players go somewhere to earn some money."

The UEFA boss revealed that they are trying to come up with an overall cap on the budget of players' salaries and transfers of the clubs that will appear in the European competitions.

"Because we don't want that two or three clubs who have unlimited resources come to a budget of five billion euros or 10 billion euros. Then our competition is not interesting anymore," he added. "Practically every club, everyone who I spoke with, agrees with that. We are far from any decision; we are just thinking about it."

Some of the biggest-spending European clubs in recent years, including Manchester City and Paris Saint-Germain, are funded by investment groups from the Middle East.