Our Gaelic Games correspondent tackles all the battles in the big game between Monaghan v Tyrone, Ulster SFC Quarter-final Clones (Sun 2.00pm).
Dermot Malone v Peter Harte
With Jack McCarron and Kieran Hughes providing the two-man full-forward line, Dermot Malone usually drops back into the half-forward line.
However, he will not have Mattie Donnelly for company as the Trillick man will be charged with keeping Paul Finlay's creativity and break-ball-winning influence down but he could instead be sent to keep Peter Harte in check.
Always willing to bomb forward, Harte has found a more forgiving home at wing-back in recent games, after his forays were exposed when he might have been minding house at centre-back.
So many of the Tyrone scores are generated by Harte, with Ciaran McGinley cleverly pulling his own marker out of the picture and over to the right wing to leave that left flank open. Malone is creative, but he will need to be a workhorse with Paudie McKenna also dropping deep and taking the ball forward from turnovers.
Vincent Corey v Sean Cavanagh
For Tyrone to win, they need a massive game from Sean Cavanagh and, unfortunately for him, it's been this way for quite some time.
Last year against Donegal he became a marginalised figure and although Tyrone tried him at centre-forward and later at full-forward, they could not get him into the game. Released back to midfield for the qualifiers, Cavanagh had one of his finest seasons ever, winning an All-Star.
However, given the leadership deficit in the Tyrone team, he needs those type of games every day.
Up against Vinnie Corey, it will be rugged and the Farney man needs to guard against an early black card as Cavanagh will drive straight through the middle from the first ball to test that Monaghan rearguard.
Kieran Hughes v Justin McMahon
With Conor McManus out of the picture, at least for a starting berth, Monaghan will require a presence in the full-forward line to accompany the more willowy talents of Jack McCarron.
Last year, Monaghan released Hughes to the edge of the square and rained high ball in from the wings to him in the Ulster final. By the finish, Jim McGuinness' gameplan and Neil McGee's reputation lay in tatters.
In previous meetings, Justin McMahon has acquitted himself well against Hughes, but there are doubts about his continued fitness and if he might have the sheer athleticism to beat Hughes in the air.
As the game wears on, or maybe even at half-time, McManus should make an appearance.
The game must be won without getting too concerned over the aesthetics of getting there.
Malachy O'Rourke has clearly been influenced by certain elements of the Donegal system. Last year, his defence was superbly constructed and frustrated the life out the All-Ireland champions, to the extent that their front six - including the talents of McBrearty, Murphy, McFadden and Leo McLoone - were rendered scoreless from play.
Dick Clerkin will be sent to test the appetite of young Conan Grugan and they will attempt to isolate Colm Cavanagh on Darren Hughes.
Colin Walshe's familiarity with Ronan O'Neill from Jordanstown should ensure a man-marking job, Drew Wylie will be on Stephen O'Neill and Fintan Kelly will follow Darren McCurry.
Without the ball, Pádraig Donaghy and Paudie McKenna will drop back and on the break, the defenders bear as much responsibility for getting scores as forwards do.
They will choke things up and make it awkward for Tyrone, who don't do well against a blanket defence.
Tyrone's two games against Down showcased all that is good and not so good about them at present.
They opened up an early gap against Down, but seemed to lose focus and concentration. Once they conceded a few consecutive scores, their mental fortitude seems incredibly brittle.
Tyrone will look to target the opposition's most creative spark so Mattie Donnelly will match up against Paul Finlay. Justin McMahon will be on Kieran Hughes with Aidan McCrory on Jack McCarron.
They could find themselves with an extra defender with Padraig Donaghy and Paudie McKenna dropping deep and while the temptation is to push up on a Monaghan sweeper, they will keep it tight for the first half.
Ronan O'Neill will drop off the front two of Stephen O'Neill and Darren McCurry to create a two-man half-forward line with Sean Cavanagh, with Ciaran McGinley and Martin Penrose busy in plenty of space on the wings.
The man in the middle
Eddie Kinsella (Wexford)
The Wexford whistle-blower was on duty in Connacht last weekend and proved he is no ‘hometown' referee as he turned down a number of borderline decisions for Roscommon against Mayo.