Ulster SFC Final Armagh v Donegal, Croke Park, Sunday 2.30: The unexpected reunion of these teams for a repeat of last year's All-Ireland semi-final has rebounded pleasantly on the GAA, writes Keith Duggan.

Although the decision to move the Ulster final to the capital was almost certainly predicated on the assumption that All-Ireland champions Tyrone would feature, the appeal of this particular pairing was under-estimated. Ticket sales during the week have exceeded wildest expectations, accentuating the dynamism of the Ulster game at present.

Armagh will see something of their own yesterdays in the young Donegal team they will meet tomorrow. Once, Armagh travelled with light-footed optimism and big dreams. But in winning the 2002 All-Ireland final, they acquired an aura of hard invincibility that very nearly carried them to a second successive title last September after a season when they got by on mental toughness and street smarts.

By modern standards, their longevity is commendable: Armagh have been a top-four team since 1999 and appear in yet another provincial final with absolutely no fanfare, just as Joe Kernan would wish. The Crossmaglen man will have seen little on the landscape thus far to upset the conviction that he can wring another All-Ireland title out of a well-travelled team.

For Donegal, tomorrow is about looking into the mirror to see what is staring back at them. Since Brian McEniff returned in the winter of 2003 to zero expectations, he and his young team have constantly confounded.

Reaching last year's All-Ireland semi-final was a fine achievement. This year, the surprise has been how thoroughly the lessons of last year have been absorbed: the team is physically stronger, tougher and more mature in attitude.

Donegal lost Ulster finals in 1993, 1998 and 2002 and it would be apt were McEniff to extend his unique record of involvement with all the county's provincial titles - they have won five.

But Armagh are not exactly laden with provincial honours and the mere fact of winning silverware could have a wonderfully restorative effect on their so-so season.

Kieran McGeeney's return is timely, reinforcing the sense of a storied bunch giving it one last shot. Armagh possess all the fundamentals: secure defence, competitive midfield and blistering forwards. Ronan Clarke will be itching for a Croke Park run after last year's season while Steve McDonnell will fancy himself to do well here.

A key area for Armagh, however, will be the ability of their half-forward trio to live with Donegal's high-octane half-back unit. Also, it will be a surprise if their midfield enjoys as much possession as last year.

Given the evolution of Christy Toye and Colm McFadden, Donegal's game is more sophisticated than last year. Their attack is no longer just the Devenney and Sweeney show.

The three-man full-forward line poses a potential problem for Armagh. Francie Bellew had a distinguished season last year but sooner or later his lack of pace is going to tell in Croke Park and that day of reckoning could be tomorrow.

Although Donegal have bulked up, they won't want to engage Armagh in a war of attrition. They will still run like gazelles, with Michael Hegarty and Brian Roper calling the shots. That their young midfield pairing of Brendan Boyle and Stephen McDermott capitalise on their heroics against Tyrone is critical. Last year Philip Loughran thrived against the Donegal midfield.

The form of Brendan Devenney has been the subject of concern but there is the sense he is due a big statement. It will be no great surprise if he tears things open tomorrow.

They know they can score against this Armagh defence but, equally, they cannot expect the Armagh forwards to be as wasteful this time round.

In a way, Donegal, all hyped up and hopeful, are sitting ducks, particularly coming up against a shrewd, proven and sometimes great team like Armagh. When Armagh click, they play a sternly beautiful brand of football that is often under-rated and is very hard to beat.

It will be bruising and close - a draw is highly plausible - and again it could hinge on an imponderable, like last year's dismissal of Ray Sweeney. John McEntee and Andy McCann of Armagh and Paul McGonigle and Kevin Cassidy of Donegal could play key roles from the bench.

But Donegal have fought hard over the past few years to earn their respect and have worked hard to put themselves in this position. They needed to acquire a mean edge to complement the flowing ball-movement.

Against Tyrone, tired champions or not, they showed the killer touch. The Anglo-Celt cup is due another winter in Bundoran. Donegal to win.

DONEGAL: P Durcan; N McGready, R Sweeney, D Diver; E McGee, B Monaghan, S Carr; B Boyle, S McDermott; C Toye, M Hegarty, B Roper; C McFadden, A Sweeney, B Devenney.

ARMAGH: P Hearty; E McNulty, F Bellew, A Mallon; K Hughes, K McGeeney, A O'Rourke; P Loughran, P McGrane; P McKeever, T McEntee, O McConville; S McDonnell, R Clarke, D Marsden.