There's big time. Then there's BIG TIME. There are football clubs and there are cultural phenomenons. David O'Leary had no doubt about which he was joining when he came to Leeds. He has no doubts about which his team faces this weekend either.

Tomorrow afternoon, live on television from Yorkshire, his Leeds side entertain, if that's the word, Manchester United. For the home side that's big time, lower case. A football club entertaining a BIG TIME cultural phenomenon who are coming off the back of one of the most storied weeks in their much-hyped history. Tomorrow they'll be living the high life vicariously, but Leeds, to some extent, are still a football club in the old-fashioned sense of the word, a team in the eye of a passionate sporting city. One foot in the business world, one foot still in the working class milieu which spawned them. O'Leary remembers one of the many pieces of advice he received from George Graham during their association. He was leaving Arsenal after his epic tenure and Graham told him that when he got to Leeds the worst thing he could do was open his mouth at every opportunity and compare what Leeds were doing with what Arsenal were doing. Not many clubs do things like Arsenal do.

"I came here with the philosophy that there are people in this world with class. Regardless of money, some people have class. Arsenal did things with class. From top to bottom. And that's what we're trying here. All the money in the world can't buy you class. That comes from somewhere else."

On Wednesday night, as Manchester United were busy inventing the wheel in Turin, O'Leary had his reserve side at Preston North End. They won handily. The modesty of the environment was only slightly at odds with Leeds United's affluence. Mankind won't benefit for centuries to come from Leeds' achievement, but it was a solid bit of business, a triumph of doing the right thing. Leeds aren't so well endowed with resources that they can field reserve teams spangled with internationals and bright young sparks.

O'Leary knows the dimensions of the gulf between his own club and their visitors tomorrow. In moments when he is being frank, he wonders if it can ever be bridged by mere good habits and good values. He has spoken frequently of the Premiership containing a league within a league. Upward mobility is the long-term challenge.

"When you see what Man U have in terms of spending power, look at their squad, the players they have sitting on the bench. That's frightening. They say we are the team for the future. Well, hopefully I'll get the backing to stabilise for next year. I don't know. I have to get my young players better and stronger, buy a few players and develop them. Meanwhile, Chelsea, Arsenal and United will buy big again. It's the league within a league."

He's hasn't got a big save-the-world plan. He reckons a salary cap will never happen, much less work in the buccaneering modern soccer environment. Pay-per-view will only make things worse. O'Leary's immediate task is to grow his own team, take risks on slightly developed prospects elsewhere and somehow to take on the super squads that hang like rain clouds at the top of the league.

By anybody's reckoning he has done well. Leeds' formline over the last nine games shows a run of seven wins and two draws. For a young team which should be jaded and erratic, that's good management, and barring a remarkable fall to earth O'Leary will be bringing European football to Elland Road next season.

He has pulled off the trick with scarce resources and in the face of an injury toll normally associated with motorway pile-ups. Nor has he been helped by the fact that George Graham's purchases last summer - Danny Granville and Clyde Wijnhard - have made little impression.

O'Leary bet all his chits on the youth card. Ian Harte's career blossomed. Harry Kewell became a fixture in the side. Lee Bowyer developed into the sort of player he once promised to be. Jonathan Woodgate, Alan Smith, Steve McPhail, Mathew Jones and Paul Robinson all made contributions of varying significance.

"I've given a chance to players that I have been watching for two years. I knew they were good enough. I want people to like us, to say we are not a bad side, that we play good football. I have spent £4 million, which is nothing. I haven't the power to spend like a Manchester United or Chelsea or Arsenal, but we are giving them a run. We are putting Leeds back on the map and supporters enjoy watching us. That's all I can do."

Dream stuff, but harsh winds from the real world whistle menacingly through a manager's office from time to time. He reckons crops of good youngsters come in cycles and with the exception of a few possibilities, Leeds have harvested theirs now. Anything else will be a bonus he will eagerly accept.

When he parted company with George Graham, the Scot told O'Leary that he had every confidence in his ability to become a fine manager in the long term, but he was entering the management gig at probably the worst time in history. The football world is infested with dodgy agents and its ozone depleted by men in suits. Willem Korsten provided O'Leary with his first shiver. As O'Leary says, the gangly Dutchman was no genius, but for £1.25 million he fitted in to the Leeds set-up as a player of promise, the sort of project the club will have to specialise in. O'Leary saw him, brought him over on loan, and was impressed. The crunch came and Korsten, who made all the right noises about staying, went home to Holland again with accusations flying over why he had changed his mind.

"I felt badly let down over that," says O'Leary. "I have a good chairman here, but it's not like the Shankleys the Revies, this is a new world, a hard world. It would be interesting to see how those people would cope. I have an excellent chairman, I have a good relationship with him, but I have a PLC side of things. They're not football people, they are money people. That is the toughest thing.

"Dealing with them and dealing with agents. There are good agents and bad. Some have only their own interests at heart. Then there is trying to explain to PLC people about footballers and they haven't a clue about the game, all they deal in is money and shares. A lot of things make up a football club and at the end of the day you are dealing with human beings and they don't always play well."

He says that so far the men in suits haven't infringed especially on his work, but there is frustration in his voice when he speaks about the process of going to ask if he can buy somebody and being given the opinion that the man in the suit doesn't think the player is right.

"I think their attitude is keep it as cheap as possible, but they want you to win the league. That's the thing. It's not that you want to know your budget for the year and tell the world what you have got. I'm being told: well we're not telling you what you've got to spend, but we won't stand in your way if you name players. "That's like saying you can buy a house or car, but you need to know what you've got to spend and then you go and look in that market. My difficulty is I don't know what market I'm looking in at the moment. If I'm told I've only £5 million to spend privately, then I have to accept that, but we are a big club, we're telling people we are a big club - pulling 40,000 people a week, never been so much on Sky etc. We have done well this year, but we can't do miracles."

That dry, tough side of things hasn't taken him by surprise, but it has been the hardest to cope with. For two years under George Graham he was given a great deal of responsibility. After Arsenal, having a name so long associated with one of football's quality brands, he got offers including one from a Division One club. Graham advised him to do things quietly. He had all the basics, but Graham felt that people thought there was nothing more to him than being a nice fella. "They didn't see the other side."

There is another side, though. He is, for instance, firm and defiant about the stance he took on the release of Irish players for the World Youth Cup in Nigeria. He took criticism from several quarters, including this one. Names stuck in his memory and when conversation provides the opportunity, he is sharp in the tackle.

"I took stick and I thought it was a disgrace. I took exception to it and I took exception to yourself on it. You all let the other fella (Brian Kerr) off the hook on it. For all you've given me stick over it, you've kissed his ass on it. You haven't played it down the line at all. If you listen to me. If I had six kids and we had been challenging for the Premiership and they had been taken to Nigeria. Do you think that that's right?"

He argues that Leeds have a system whereby once players have passed through the youth team and played for the first team there is no going back. The bottom line at Leeds is not to win the FA Youth Cup, but to get through and play in the Premiership. "Take Robbie Keane at Wolves. He is a full international and playing superbly well. What was Robbie Keane doing there? I'm all for it, all for the Irish youths. What is Robbie Keane doing there, though? You don't know how much that has put Irish football back. Everybody in England is asking, is he (Brian Kerr) chasing the tin-pot glory himself or is he looking after the interest of the kids?

"UEFA should say that once kids are playing in the first team, they are finished with youth football. I really think it has done us harm over here. For all that I got stick about it, I was only trying to make a point.

"UEFA should make a stand for the good of everybody. England did it, but I know Brian Kerr would say that they have enough players. They haven't. They have good players, but they knew going out there they weren't going to win it. We went and took our best squad out there."

He is polite, but emphatic in arguing the point. "Give me a break," he says more than once. The debate rolls on for a while, but the perspectives of club and country are irreconcilable. Will it lead to more Jamie McMaster situations (McMaster is the Australian teenager who Leeds recently insisted play for England), he is asked?

"Only time will tell," he says, mildly exasperated. "I just thought it could have been handled a lot better."

He says his piece and moves on without rancour, looping back to the subject just once to balance his remarks by saying that Steve McPhail came back from Nigeria in splendid shape, that it was obvious that a good job had been done looking after the players.

"I don't want to seem as if I'm down on everything." He isn't. He enthuses about players a lot, talks about Dublin whenever the chance occurs. There is something avuncular and old fashioned in his manner which makes it easy to see why he is good with young players.

"Being a good young player doesn't mean they act different you know," he says. "I demand that they treat people with manners and courtesy when they travel. Treat people well. Just because somebody gets £100 a week working in a restaurant, you have no right to come the big shot with them. That could be my Mam or my Dad doing their job, earning a living. I won't tolerate any of that crap."

He is a peculiar fish. A deliberately mild-mannered man who inspires strong opinions in people. Three research phone calls about him produce three wildly different but equally forceful views and no consensus at all. O'Leary takes it all in his stride, or appears to at any rate. His version of stepping over the threshold into management has no clarions or trumpets.

"We played Chelsea on Sunday. I came in on Monday and just said I'm the boss now. I used to deal with them a lot on my own, so it wasn't a big deal."

Oh. And because he is pathologically polite, he expands: "I take a deep breath sometimes. It's hard to appreciate that a kid growing up in Dublin could be this lucky. Winning all those things, having such a long career, and then what a first job, what a high-profile first job. I'm a lucky fella."

He'll have some measure of how lucky by teatime tomorrow. Leeds play all the teams in the "other Premiership" as their season winds down. Against Manchester United, Chelsea and Arsenal, he'll get a better measure of his team's potential than he has had in the last nine unbeaten games.

He knows his players are starting to tire and the knowledge that he can't rest them irks them. Harry Kewell has been motoring all season on a young man's battery.

"I think of Kevin Keegan and he worked a miracle at Newcastle, but he spent £60 million getting them buzzing again. I've got Leeds buzzing now for £4 million and I know I'm not going to get £60 million from anyone. Keeping it that way, keeping it buzzing, well that will be the real miracle."

This weekend he tests himself against the dream again. Tilting at windmills is what sport is all about, so roll up, roll up, roll up.