O'Neill believes Villa have to discover this quality if they are to have genuine aspirations of breaking into the elite group of teams who constantly dominate the Barclays Premier League.

He is a particular admirer of leaders Chelsea even though Villa defeated them 2-1 earlier this season.

Villa have produced some outstanding performances this season in challenging for a European spot but also dropped points against Wigan Athletic, West Ham United and Wolverhampton Wanderers.

O'Neill said: "Look at Chelsea. They are so strong. I tend to mention them more than any of the other top-four sides but they have a great mentality, work ethic and they are physically very strong.

"It is almost burned into them that winning football games is what it's all about. This winning mentality is vital. It's keeping them going.

"We need that winning mentality as well. It is so important. I can't stress it enough. It's not about being just nearly there, not about 'that's not so bad.'

"It's about a genuine winning mentality.

"We must go out and win football matches - that's the be all and end all. The number one aspect of that is going into every game believing genuinely you can win it.

"I think we have that but it can stagnate and dissipate during the course of a game if you're not mentally strong.

"It's remaining mentally strong and mentally tough throughout the game. You're going to have setbacks throughout the course of football matches. It's having that ability to fight back from those."

Villa have won four and drawn one of their last five fixtures in front of their own fans but have not won in five on the road, to reinforce O'Neill's point about the importance of grinding out victories.

On Saturday they host a Tottenham Hotspur side still on a high from thrashing Wigan Athletic 9-1 and O'Neill could call upon his big summer signing.

Winger Stewart Downing bolstered his hopes of making a home debut against Spurs after completing 75 minutes for the Reserves against Arsenal at Underhill on Wednesday night.

O'Neill's £12m summer capture from Middlesbrough made a late appearance as a substitute against Burnley - his first senior action for Villa - in last weekend's 1-1 draw at Turf Moor.

The England winger suffered a broken foot in April, ironically in a tackle by Villa skipper Stiliyan Petrov.

Central defender James Collins is again a doubtful starter to face Harry Redknapp's side with the groin injury which forced him out of the meeting with Burnley.