Whether or not Cian O'Sullivan plays on Sunday week will have a huge bearing on the outcome of the All-Ireland final.
The Dublin centre-back pulled up right at the end of last weekend's brilliant semi-final replay win over Mayo.
He's had hamstring problems in the past and if it's any sort of serious tear two weeks won't be enough to get him right.
If he does play, and I suspect he'll start regardless, it would be interesting to see someone like Darran O'Sullivan, a player with deadly pace, testing out the Dublin sweeper.
O'Sullivan is the key man in Jim Gavin's defensive strategy and that sweeping role is something that he has worked on for the last 12 months or more. He won't be easy to replace.
He plays the role to perfection because he is seriously quick and he can read a game beautifully. He knows when he's covering his full-backs that he has to be close to them - not leaving too much of a gap.
The sweeper has to be close enough to the opposition danger man to discourage ball being played directly in to him. And if it does come in, he has to be close enough to him to get the breaks off the full-backs and then turn them into quick attacks.
When he's in possession, he's just a gorgeous solo-runner and his awareness of space is sublime. I know myself that I'd be a hell of a lot more confident about Kerry's chances if O'Sullivan wasn't playing.
There were questions marks about Dublin after their late collapse in the drawn game with Mayo and they answered most of them last Sunday.
Their forwards are particularly impressive with their physical power, movement, dynamism and pace. They have a huge spread of scorers and if Diarmuid Connolly isn't doing it one day, Paddy Andrews picks up the slack. If Paul Flynn isn't on his game, Ciarán Kilkenny does the business and so on.
Then they've Kevin McManamon and Alan Brogan coming off the bench, both players with great experience and proven records of changing games.
They weren't tested through the championship until the past fortnight, but now they've had two searching exams inside six days and have two weeks to prepare for the big day - that's perfect scheduling and it has fallen just right for them.
We saw both days against Mayo, particularly in the replay when Philly McMahon got 1-2 off Aidan O'Shea, how their corner-backs like to get up the field.
The question for Kerry is do they ask players like James O'Donoghue and Colm Cooper to follow them all the way back? I don't expect that.
I believe that they'll let McMahon and Jonny Cooper go, trust that they'll be stopped, turnovers will be forced and scores come from the quick ball in.
If Kerry can succeed in this once or twice early on, it'll pin those two boys back.
We all know about Stephen Cluxton and his kick-outs and after a mini-meltdown in the drawn Mayo game, he looked more assured in the replay, though it's easy to have a 100 per cent record when you're hitting your corner-backs 20 yards away for the most part.
This is another real area of strength for them. I thought Mayo took a good policy the first day, not pressing his kick-outs and letting him take them short to players who aren't as good as distributing as he is and making them work the ball from a long way back. This increases the potential of getting a turn-over. However, they seemed to be caught betwixt and between the last day and it just shows the importance of having a Plan A, B and C in this area.
The half-backs are another area of massive strength for the Dubs, with James McCarthy and Jack McCaffrey so assured on the ball and they push forward with pace and intent.
Their midfield hasn't gotten much credit this year, but it's hard to get credit when the kick-outs are going to corner-back. I believe the Brian Fenton and Michael Darragh Macauley will start there the next day.
Overall, Dublin are a brilliant team. They showed they had the mental toughness at four down against Mayo, though it would have been interesting to see what happened had Lee Keegan kicked that point to put them five up.
They have a strong bench and Jim Gavin knows how to time them to perfection.
But there are question marks. The form of Paul Flynn and Dean Rock has to be a worrying.
Also, I'm not sure about their discipline. It was shocking in the drawn Mayo game and whilst it improved last weekend, it isn't something you turn on and off.
I made a note of their lack of discipline when they played Kerry in the league and when a manager shakes a player's hand coming off the field after he gets a red card it sends out a message.
NEXT week will provide a better opportunity for an in-depth analysis of the football final so, for now, a short teaser on the never ending challenges a team will face in their quest to overcome the opposition and win the Sam Maguire.