Legendary Manchester United boss Sir Alex Ferguson has revealed that he passed up the opportunity to sign David Silva during his Valencia days over a lack of defensive work.

The 29-year-old playmaker has helped Manchester City to four major trophies - including two Premier League titles - since joining from Los Che in 2010.

Silva, who cost the Citizens £24m, also won a World Cup and back-to-back European Championships with Spain, and Ferguson says that he could have been on the red half of Manchester instead - if not for a work-shy attitude.

"We watched Silva a lot when he was at Valencia," the Scot, who retired in 2013, is quoted as saying by The Mirror. "And the other player they had, the same type, years before it, played in that No.10 role.

"My problem with that was you have to be very, very good to play in that position, because there's no defensive duties for them. So if you're wanting to be be really successful, everyone has to do their turn, has to work, you know?

"So I had a difficulty with that. But, in the end, of course, there's the greats. You could say Lionel Messi was a No.10 type, Maradona, some fantastic players, and I don't dispute that. But at United we always found it difficult. The kind of No.10 I used came from my experience as a footballer."

Silva has notched over 70 assists for the Sky Blues in all competitions.