Cristiano Ronaldo has claimed he “doesn’t agree” with centre-backs and goalkeepers being sold for “€70 or 80m” and believes a player who scores goals is worth “three, four times more, easy”.

The Juventus forward, who became the world’s most expensive player when he left Manchester United to join Real Madrid for £80m in 2009, believes inflation is causing clubs to gamble on players before they’ve proved their worth.

The five-time Ballon d’Or winner specifically mentioned the price of defenders and goalkeepers with Harry Maguire’s £80m move to United from Leicester breaking the world record for a fee paid for a defender this summer.

Ajax’s 19-year-old captain became Ronaldo’s teammate at Juventus this summer, joining for £67.5m after protracted negotiations with a number of Europe’s top sides.

“It’s difficult to make calculations in modern football,” Ronaldo told Portuguese channel TV1. “[Clubs] gamble a lot on potential and the football industry is different.

Top 10 highest paid footballers in the world Show all 11 1 /11 Top 10 highest paid footballers in the world Top 10 highest paid footballers in the world Who are the top 10 best paid players in the world? Soccer Football - La Liga Santander - FC Barcelona v Eibar - Camp Nou, Barcelona, Spain - January 13, 2019 Barcelona's Luis Suarez celebrates scoring their third goal with Lionel Messi and Philippe Coutinho REUTERS/Albert Gea ALBERT GEA REUTERS Top 10 highest paid footballers in the world 10. Mesut Ozil, Arsenal £1.4m/month Reuters Top 10 highest paid footballers in the world 9. Kylian Mbappe, PSG £1.5m/month AFP/Getty Images Top 10 highest paid footballers in the world 8. Alexis Sanchez, Man United £2m/month Getty Images Top 10 highest paid footballers in the world 7. Philippe Coutinho, Barcelona £2m/month AFP/Getty Images Top 10 highest paid footballers in the world 6. Gareth Bale, Real Madrid £2.2m/month REUTERS Top 10 highest paid footballers in the world 5. Luis Suarez, Barcelona £2.5m/month AFP/Getty Images Top 10 highest paid footballers in the world 4. Neymar, PSG £2.7m/month AP Top 10 highest paid footballers in the world 3. Antoine Griezmann, Atletico Madrid £2.9m/month REUTERS Top 10 highest paid footballers in the world 2. Cristiano Ronaldo, Juventus £4.1m/month EPA Top 10 highest paid footballers in the world 1. Lionel Messi, Barcelona £7.3m/month Getty Images

“Leaving the case of Joao Felix to the side, any player can go for 100 million euros, even without showing anything.

Harry Maguire became the world’s most expensive defender this summer (EPA)

“There is more money in football. A centre back and a goalkeeper can go for 70 or 80 million euros. ”I don’t agree [with it] but it’s the world that we live in and you have to respect it.”