Rio Ferdinand has been warned he must devote his whole life to Manchester United if he wants to become director of football.

The former United defender has spoken to executive vice-chairman Ed Woodward about taking over the role.

But an expert in the field believes Ferdinand must understand what he's getting himself into before accepting the position.

Andy McIntyre, who trains ex-footballers to move into the boardroom at VSI Executive Education, said: "The sporting director is running the football side of the club, the medium to long-term strategy and vision.

"If you look at Manchester United, there has been no football strategy whatsoever since Sir Alex Ferguson left.

"They scream out as a club who would benefit in having someone as bright as Rio sitting there as director of football.

"It's a full-time, intense, hugely responsible position. And if he is doing that, then everything else has to go from TV appearances and other business.

"If you are serious about it, at a club like United, the level of responsibility is vast.

"We know of people who are up at five in the morning, do a day's work and then fly off to Paris to watch a player.

"They are then back in at their desk first thing the following morning.

"If you want to be director of football at Manchester United, it is something you need to be hungry for and are willing to commit absolutely to."