Mick McCarthy has already turned his sights on a "cup final in the Aviva" to book a ticket to the Euros and admitted Matt Doherty will start in the absence of the suspended Seamus Coleman.
The Republic of Ireland could have qualified tonight but they failed to fire in the first half of a 2-0 defeat to Switzerland.
Haris Seferovic's 16th-minute drive and an injury-time own goal from Shane Duffy did the damage, with Coleman seeing red for a second yellow in the 76th minute that led to a penalty, which Darren Randolph saved.
The opening period was riddled with sloppy Irish play in possession, but they were far better on the turnaround, rattling their hosts before fading after Coleman made his exit.
"We were beaten by the better team, considerably the better team actually, certainly in the first half when we didn't play particularly well," McCarthy told RTÉ Sport's Tony O'Donoghue.
"Whatever system we're playing it doesn't excuse our wayward passing and some of the stuff we did. I changed it around it and that settled it down a bit in the second half. We played far, far better. I think it was a performance we can be proud of.
"The second half, with ten men, they had a right go. They're a big, powerful, strong side as well. They stopped us. But I think it showed in the second half that we are capable of doing it."
McCarthy had started with a 3-5-2 system, deploying Coleman and James McClean as wing-backs. It didn't work, though the manager put that down to collective ineptitude rather than the formation causing confusion.
"It didn't cause us not to pass the ball to each other that's for sure," he said.
"If in changing (the system), that's the root cause of it, I'll accept responsibility for it. But I'm not accepting responsibility for our inability to pass it to each other in the first half. We were really poor."
There were some bright sparks. Glenn Whelan impressed in the holding role, while Aaron Connolly got 70 minutes under his belt on his first senior start. Both earned praise from the boss.
"Glenn was brilliant. He's an example to all young pros.
"Aaron can be proud of what he did. He's playing in a side that didn't play particularly well in the first half. I just reminded him that I took Kevin Kilbane off when he made his debut and he went of to make 120 appearances or something.
"Aaron will be disappointed that he's not had any real chances... but he can be proud of the fact that he's in the first team and he's got loads more games to come. I'm pleased with him."
McCarthy had no complaints over the spot-kick. With captain Coleman now out of the Danish showdown, Wolves man Doherty will get his chance at right-back.
"In this day and age yes (it's a penalty). He's got his hand in front of his face. In medieval times when I was playing it probably wouldn't have been but it's changed. It's hit his hand, it's in front of his head, it's not in a normal position, so it's a penalty.
"Matt is in the box seat now to be playing. He's a Premier League footballer so there's no issues there.
"To get first or second (in the group) it was always going to be an over-achievement I think when you look at the two teams. We've still got a chance to do it. A Cup final in the Aviva on 18 November, I'd have taken that before and I'll take it now."