Cristiano Ronaldo’s agent, Jorge Mendes, has denied the reigning Fifa World Player of the Year is unhappy at Real Madrid amid reports that Manchester United are interested in re-signing him and insisted he can play on into his 40s.

United have been exploring the possibilities of financing a move for the player they sold to Real for a then-world record transfer fee of £80m in 2009, with the Portuguese rumoured to be open to a move back to Old Trafford. However, in an interview with the Spanish radio station Cadena COPE on Wednesday evening, Mendes rejected those suggestions and was adamant Ronaldo intends to spend the rest of his career in the Spanish capital.

“Cristiano is very happy at Real Madrid and has always been very happy,” Mendes said. “He’s going to break all the records with Real Madrid and he’s going to retire here. He has a lot of love for United because his heart was there for six years, but now he’s only thinking about Real Madrid and he’s going to stay here forever. He’s incredibly happy. It’s one thing to respect the people who remember him but he’s with Madrid to the death. We didn’t receive any offers for him because people know that it’s impossible to take Cristiano from Real Madrid, therefore, it’s not worth it to even call and ask about him.”

Ronaldo scored his 26th hat-trick for Real in the 5-0 win over Athletic Bilbao on Sunday to take his tally for the season to 13 goals in just six La Liga matches. Mendes expects his client to continue improving while claiming there will not be another player like him “for the next 500 years”.

“He gets better every time and he’ll continue to get better into his 40s,” he said. “Along with being the best player, he’s the best athlete in the world. Nobody compares to him. There won’t be anyone like him for the next 500 years. He’s a very humble person and a family man. A fantastic father. He’s the son any mother would love to have. He’s concerned about others. There are so many great things about him that it’s impossible to list all of them.”

Mendes added: “Cristiano’s dream is to win another Champions League. His dreams are always short term. He’s never satisfied and he always wants more. He never stops surprising me. It’s impossible to find anyone like him in the history of sport.”