Martin O’Neill was showing concerns over how much money Aston Villa owner Randy Lerner would make available for new signings only 72 hours before quitting the club.

O’Neill dropped a bombshell yesterday by ending his four-year reign in charge of Villa just five days before the start of the new Barclays Premier League campaign.

Reserve-team coach Kevin MacDonald will be in charge for Saturday’s league opener with West Ham at Villa Park.

James Milner’s £20million-plus transfer to Manchester City is earmarked to be completed after the midfielder has returned from England duty later this week.

And there has also been speculation that winger Ashley Young - hailed a “genius” by O’Neill - could be tempted away from the club with Tottenham thought to be interested.

It is unclear at this stage whether any development regarding Young was the final straw for O’Neill.

But the former Celtic boss had indicated before the weekend that he needed to speak to Lerner about what funds would be at his disposal.

Now the Northern Irishman has called time on his spell at Villa.

O’Neill seemed less than convinced that he would receive all the money for new signings from the Milner deal when asked about the situation after the friendly clash with Valencia.

In response to being told Lerner had said money raised from selling players would be used for new signings, O’Neill said: “Did he?”

He then added: “I need to speak to the chairman.

“For a number of days in this transfer saga with Manchester City, you have known my position in terms of what I have been advocating and thinking about.

“But it really has been the chairman (Lerner) and chief executive (Paul Faulkner) who have been dealing with it.”

Lerner has backed O’Neill fully in previous summers and 12 months ago Stewart Downing, Stephen Warnock, Fabian Delph, Richard Dunne, James Collins and Habib Beye cost a combined £40million.

But this year the American businessman had said he would prefer to implement a “sell-to-buy” policy at Villa.

In addition to Milner’s likely departure, six other players had been made available for transfer but so far none of them has left Villa, including Luke Young who rejected a move to Liverpool.

O’Neill was hailed by hundreds of Villa fans when he arrived at the club as successor to David O’Leary in 2006 after a year’s break from the game.

There has been a steady upward progress with Villa finishing sixth in three successive campaigns and last season also reaching the final of the Carling Cup.

But at the end of last season O’Neill, recognising the progress made by Manchester City and Tottenham, conceded Villa “had to improve just to stand still.”

To date he has not made a single signing during the close season.

Perhaps O’Neill, not the kind of manager content to just tread water at a club, felt he would not have the backing to realise his dream of Champions League football.

But that will not become clear unless Lerner, not known for making public statements, breaks his silence on losing the services of O’Neill.

He had predicted in May that O’Neill would stay after an earlier bout of speculation surrounding the ex Leicester boss which had started on the internet.

But O’Neill never made a public response to Lerner’s statement and now has decided to call time on the latest chapter in a colourful and mainly successful career.

In a statement released by the club, O’Neill said: “I have enjoyed my time at Aston Villa immensely. It’s obviously a wrench to be leaving such a magnificent club.

“I would like to pay tribute to the Villa players, my coaching staff and the Villa supporters for all the support and encouragement they have given both the club and me personally during my time as manager.

“I wish them all the best for the future. I will obviously be assisting the club in the immediate short term with regard to the handover of my duties.”

Chief executive Paul Faulkner added: “The club would like to thank Martin for the great work he has done at Aston Villa over the past four years.

“He has helped to establish the club in the upper echelons of the Premier League, has taken us to Wembley and we have also qualified for European competition for the past three seasons under his management. We wish him the best in the future.”