Only if the Leeds United chairman Peter Ridsdale had got his way could tomorrow morning's encounter between Leeds and Manchester United have been more eagerly or anxiously anticipated. Ridsdale suggested that when the original fixture was cancelled due to the Mancunians' trip to Brazil, a perfect replacement date would be the week after the FA Cup final, a soul-devouring scenario involving a virtual play-off for the title similar to Arsenal's at Anfield 11 years ago.

Ridsdale's presumptuousness was admirable; that the championship would be between just two clubs come the middle of May and that they would be the pair occupying the top two positions today. Certainly Leeds have impressed with the durability of their challenge in David O'Leary's first full season in charge, but tomorrow will offer a barometer of just how fast they are maturing. "Young and naive," O'Leary's motto, will not be applicable any longer if Leeds win.

It is two-and-a-half years since that happened, a David Wetherall header giving Leeds all three points in a 1-0 win. Last season Leeds lost 3-2 at Old Trafford and drew 1-1 at Elland Road. This season they have again been beaten at Old Trafford, Dwight Yorke scoring two late goals.

However, it is a mark of how much respect Alex Ferguson has for O'Leary's team that he is flying Yorke home from the Gold Cup, which is taking place in the US, just for this game. Teddy Sheringham can expect to make way for the returning Tobagan.

"Leeds have got to be the main threat now," Ferguson said yesterday. "You can't dismiss them at all." Ferguson concurred with Ridsdale to an extent when discussing the date of the fixture. Both sides will have 13 matches after this one and Ferguson said: "It's a big game on Sunday, but there are bigger games. It's a test for all of us, but what's crucial is when we get to the last four or five games. Then, if you make a mistake, it really means something. That's when bums start to twitch."

Ferguson then switched his attention to the heavy atmosphere that is sure to prevail at Elland Road. "There is hostility there that borders on the dangerous," he said of the Leeds stadium. "Why the police don't do something about it I don't know."

With Roy Keane sent off last Saturday and Leeds charged by the Football Association for their part in the brawl with Spurs, Ferguson is aware of the possibility of any tackle or verbal abuse being regarded as inflammatory behaviour. "Discipline in this particular game is always a concern," he said. "But I've addressed that situation. I always do before this particular match and I've had a word with them about dissent. It's so futile, you just can't win.

"If you look at the statistics we are the cleanest club in the country, but we need to iron out some of the dissent."

O'Leary is similarly concerned about loose tongues and yesterday lunchtime had the man from The Sun escorted from the Leeds training ground for daring to raise the subject of the Spurs scrap.

With Michael Duberry suspended, Leeds need their captain Lucas Radebe to overcome the niggle he picked up in the African Nations' Cup.

"We've got injuries and I'm not playing mind games when I say that," O'Leary said, no doubt playing mind games. David Batty is definitely out after missing two reserve matches this week. Michael Bridges has an ankle injury and would be replaced by Alan Smith. Stephen McPhail and Harry Kewell are both expected to be fit.

Twenty-year-old McPhail should find himself up against Keane, the man he may partner for the Republic against the Czechs next Wednesday, and O'Leary singled Keane out as the man his players should aspire to emulate. "I don't know any of the Man United players apart from Roy Keane," said O'Leary. "If Roy Keane played five-a-side on a Sunday afternoon, he would still want to win. That's the kind of man he is. It's not about money, it's about the game."

McPhail spoke recently about the importance of playing without fear and it was a theme O'Leary warmed to. "My players have never been afraid of Man United and they won't be on Sunday. My players want to be what Man United's are, they want to win what they've won and achieve what they have achieved." How the hunger manifests itself tomorrow will be pivotal to the outcome. As will referee Peter Jones. Let's hope he brings his tin hat.

Leeds United: (probable) Martyn; Kelly, Radebe, Woodgate, Hart ; Bakke, Bowyer, McPhail, Wilcox; Kewell, Bridges.

Manchester United: (probable) Bosnich; G Neville, Stam, Silvestre, Irwin; Beckham, Scholes, Keane, Giggs; Cole, Yorke.