Agent says Mourinho could stay at Chelsea ‘more than 10 years’United keeper David de Gea will see out final year of contract

Jorge Mendes has cast doubt over Louis van Gaal being the best manager for Manchester United, with the agent claiming only the “genius” José Mourinho could have built on the successful 26-year tenure of Sir Alex Ferguson.

Mendes, who represents Mourinho, also said he expects another client, David de Gea, to remain at United until at least the end of his contract in summer 2016.

Mendes told the BBC that Ed Woodward, the executive vice-chairman, can bring Manchester United further success after last season’s barren campaign under Ferguson’s successor, David Moyes, but added: “At the same time, he has just one problem – it’s completely impossible to find someone like Sir Alex Ferguson because he’s a god, he’s a genius and to find a genius is very difficult.

“You have one in England – José Mourinho. Having Sir Alex Ferguson ensures at this moment you have 12 or 15 points more. He’s finished his career, but he’s someone that makes the difference.”

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Mendes said, though, that Mourinho, who is in a second spell at Chelsea, will remain at the west London club in the long-term.

“José will stay for sure. He will be the Sir Alex Ferguson of Chelsea. He loves the supporters, he loves the city and I think he will stay there for more than 10 years.”

Of De Gea, who is yet to sign a contract extension, Mendes said: “He has one year left on his contract and I think that he will stay in Manchester. The player will decide, but he’s happy there, at the moment.”

Mendes also again stated that another of his players, Radamel Falcao, who is on loan at United from Monaco, may not sign permanently. “If he will not stay in Manchester, he will play for sure in one of the biggest teams in Europe,” he said.