Football: Keith Duggan contemplates the absorbing context and enthralling subplots as the giants of Ulster football prepare to resume hostilities at an expectant Casement Park tomorrow

"Mickey Harte believes in not playing challenge games. The result is that Tyrone play fewer matches but they all become meaningful. And I would imagine that the in-house games the teams play at training are similarly intense and worthwhile."

The observation of Donegal manager and Tyrone native Brian McIver comes at a time when Tyrone's barnstorming tour of the province suggests no let-up in performance, enthusiasm and application from the remarkable All-Ireland champions.

Fielding a team of novices and established players, McIver's Donegal team experienced the archetypal swing of fortunes against Tyrone last Sunday in Ballybofey. His first defeat as manager was useful. The team raced into an early lead and could realistically talk about winning in the dressingroom at half-time.

"Then in 15 blistering minutes they just turned the game on its head and went three points up on us," says McIver.

"The first thing to be said about Tyrone is that they have a great pool of talent. Young Tommy McGuigan - a brother of Brian - and Raymie Mulgrew just looked so comfortable on the ball out there against us. Like they belonged there.

"Tyrone have a system that means every player knows what they are doing. And even if a team manages to play well against that system, they have players like Stephen O'Neill or Seán Cavanagh or Owen Mulligan - you could keep on naming - who are capable of working a score from nothing. And it is that threat of individual talent working in a really harmonious system that sets them apart."

Donegal trooped off the field having been reacquainted with the difference between playing against the top team and being the top team. A remarkable crowd of 11,000 showed up in Mac Cumhaill Park, in keeping with the huge interest Tyrone's performances in the McKenna Cup have generated throughout January. The healthy attendance reflects the insatiable appetite for Gaelic football in the country over the past few seasons, but more locally, it represents the vitality of the game with Tyrone at present.

Their latest win sets up a tantalising semi-final with their neighbours Armagh. It may be the McKenna Cup and it may be January but this is the first meeting between the counties since the unforgettable Ulster final and All-Ireland semi-final jousts of last summer.

"And I think there will be a big crowd in Casement too," predicted McIver. "For a start, you have what I consider to be the best two teams in the country on show. And Armagh have always been more than a match for Tyrone. Armagh kind of set the tone in terms of the professional approach and Tyrone learned from that.

"This is still the McKenna Cup, a competition that has always been about trying new players and learning a wee bit about yourself. That much won't change.

"And I don't think the result will have any bearing on what might happen between the counties later in the year. But it has the potential to be a great game. I think both teams will be keen to avoid losing . . . because they know that no matter what happens here, there is probably going to be a kick of a ball between them the next time out anyway."

The prospect of the Ulster giants going at it hell for leather in front of a busy house in Belfast substantiates the theory that football has undergone a micro-revolution in mid-Ulster. Certainly, it is beyond dispute that the Armagh-Tyrone rivalry is one of the most fascinating chapters in contemporary Gaelic games. Tyrone's stunning haul of two All-Ireland titles in three years marks them out as special, but it was Armagh's historic 2002 victory that spurred Tyrone to those new heights.

After Tyrone famously expelled Kerry from the championship in the 2003 All-Ireland semi-final, Ryan McMenamin paid the ultimate tribute to Armagh: "It was more that just in January, after seeing Armagh win the All-Ireland in 2002, we came back as different players."

As a compliment, you cannot get much higher. Since then, Tyrone have moved on as a team and look well placed to replicate, in the decade ahead, the success of the past three years.

"It's a big county, with something like 48 clubs, and there is a strong ethos there," says McIver. "A lot of people have done tremendous work with development squads so the county senior squad is well catered for with talent coming through. And that is paying dividends in that the senior players do a lot of work with youngsters in their own time.

"But it wasn't an overnight thing. I suppose there was a time when the accusation flying about Tyrone was that all the underage success wasn't transferring to the senior side. Until that breakthrough was made, Tyrone couldn't take the next step. But now you have a team that knows how to win All-Irelands. And it is a fairly young team, probably an average age of 25 or 26. And over the coming years, it seems possible that the management can bring in two or three young player every season so that there is a fairly gradual and seamless change in personnel over the next 10 years.

"Even with the retirement of Peter Canavan, the team had learned to become less reliant on him and his performances were less significant than they had been a few years ago. He is still a huge loss but Tyrone are capable of replacing him now in a way they couldn't have a few years back."

Canavan's parting gift to Armagh was to deftly slide over the free that sent the Ulster champions crashing out of last year's All-Ireland championship.

There is a sense of unfinished business about this Armagh team and predictably all of their great warriors have reported to training this week.

The burning will that drives Armagh has perhaps best been manifested in the efforts of their midfielder John Toal to recover from a badly broken leg sustained during last year's Ulster final. His ambition and determination to play for Armagh again has been relentless - and if and when he takes the field in an orange shirt, it will represent another vindication of the unique Armagh spirit.

Of course, there are no guarantees. The one thing Toal knows is that he won't win his place back for sentimental reasons. In Armagh and Tyrone, there are plenty of exceptional young players bursting for a chance to perform at senior level. The McKenna Cup is their chance to shine.

And for the thousands who will head for Casement tomorrow, it is a game to whet the appetite.