Silva reveals Los Che needed to sell him to balance the books.
He told the Manchester Evening News: "Why did I leave Valencia? Because the club needed me to," he said. "I was happy there and I wouldn't have left, but the situation the club was in demanded it.
"It was a big injection of money and it was good for them. My life has always gone step by step. I suppose it was time to take the next one.
"City showed a great interest and I wanted to settle it quickly. It was a very interesting offer, a good club and I didn't have to think too much. Everyone agreed and I'm very happy."