"It was a great honour to coach him. I wish him and his family all the best, and I want to thank him for what he did at the club last season," said Guardiola.
"We had a lot of problems at the start, especially in the centre of the pitch, but he was always there when we needed him. He always played.
"We tried to get him to stay, but I understand. He's young and wants a new challenge. It's his choice and we have to accept that. I hope he's happy in Madrid."
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