We know most of what Martin O'Neill's line up will be for Ireland's opening game of Euro 2016 on Monday.
Darren Randolph will almost certainly start in goal, it will be Seamus Coleman at right-back, likely Robbie Brady at left-back and John O'Shea captaining the side from one of the centre-back berths.
Who will partner O'Shea in central defence is a little bit less certain.
Ciaran Clark was excellent in the two playoff games against Bosnia. The Aston Villa centre-back's partner for that game was Richard Keogh.
Back in March, we spoke to Steve Nicholson from the Derby Telegraph. He told us that this season, Keogh has been Derby's best player as the team finished fifth in the Championship and exited the playoffs with a semi-final defeat to Hull.
Keogh has probably been Derby's best player this season. He faced some fierce criticism from fans after that, he had the captaincy stripped off him by Paul Clement, but he has bounced back.
A few fans really had a go at him [after the error in the play-off final] which was totally unfair because mistakes happen. That drifted into the next season. Derby messed up, went from first to eighth, promotion dreams were shattered for a second time and he took a lot of the flak. Now he has really bounced back.
Martin O'Neill's other option is Shane Duffy.
This has been the 24-year-old's breakthrough season for Blackburn Rovers. He started all but five games in the Championship.
Paul Wheelock of the Lancashire Telegraph believes that bar two others, Shane Duffy was probably Player of the Season for Blackburn.
Grant Hanley, the Scotland player, was Player of the Season. You had Ben Marshall, a versatile player was up there aswell but Shane was too. He said it himself, he had a few games where he didn't play well or made a mistake here and there but overall he was fairly consistent and was one of Blackburn's players. He definitely came on leaps and bounds this season compared to his first season at the club, where he got a bad injury to be fair. He's had a really good season.
2015/16 was a poor season for Blackburn. They finished in 15th, closer in terms of points to the trap door rather than the ladder out of the Championship.
The Blackburn defence was not a factor in this disappointment. Realistically the back four - especially Duffy and Hanley - were the reason the club did not flirt more with relegation.
Blackburn have had a fairly poor season but defensively they were good. I think it was just the top six and one other team that had a better defensive record and that's testament to Shane and Grant and the other defenders but particularly Shane and Grant.
In terms of physicality, Duffy is exactly what you would look for in a centre back. He stands and imposing 6' 3", creating a sturdy defensive barrier. He is also becoming a vocal leader on the pitch.
In the air, he's absolutely superb defensively. He probably should have scored more goals at the other end of the pitch. But as an out and out centre-back in terms of getting his body in the way and blocking things, winning headers, he was rock solid for most of the season. You can see that there's more to come from him and that he's growing in the game.
He's getting more vocal, you can tell that. Him and Grant Hanley have a really good partnership. They're both young, only 24 at the moment but you can see he's growing into his position at the club. He's becoming more of a leader and more vocal. You can see the high standards that he demands from his teammates aswell.
Duffy is likely more comfortable with the ball in the air rather than on the ground but that does not mean he's a defensive liability.
He's said it himself, he'd like to get a bit better on the ball in terms of his distribution but when he's made a mistake this season they've been obvious mistakes. I think there was a backpass for one goal and he handled the ball on the line but to be fair there have been very few times this season where I've come away thinking 'Alright, he's had a poor game there.'
The Derry man's potency in the air is not just defensive. At set pieces, he is a major threat.
If there's little to differentiate between centre-backs for Martin O'Neill, it could be the threat which Duffy's presence, coupled with Robbie Brady's delivery, would create that swings his decision.
During the friendly against Switzerland in March, it was Brady, Duffy and Clark who combined for what turned out to be the winner.
2: GOAL!
IRELAND 1-0 Switzerland.
Ciaran Clark heads home to give Ireland the perfect start. https://t.co/QLd4LaRUuj— eir Sport (@eirSport) March 25, 2016
Duffy hit the back of the net four times this season and has said himself that he should have scored more. His stats in terms of shot on goal, for a centre-back, are remarkable. This season: 73 shots on goal, 21 on target. Those numbers do not surprise Paul Wheelock.
He would probably admit himself that he should have had double that. He's got real attacking strength in the box. If he doesn't score himself he'll create chances for others. He's a big threat in the opposition box but remember, he's a centre-back at the end of the day. It's probably a bit much to be asking him to score eight or nine goals.
Late in the season, he grabbed two winners. There was a header in the penultimate game of the season against Rotherham.
There was also rifled finish against Brentford with Blackburn down to ten men after the sending off of Grant Hanley.
Photo by Matt Browne/Sportsfile
