Celtic CL post-mortem: What went wrong and where do they go from here?

Celtic were on the wrong end of a historic LASK Champions League comeback to deny Martin O'Neill's side a spot in the league-phase draw; Sky Sports News' Anthony Joseph takes us through the implications after Celtic miss out on the Champions League for the second straight season

Celtic have spent the last couple of years making Champions League qualification look like a problem they simply cannot solve. But even by their recent standards, this was a collapse of remarkable proportions.

Four goals ahead with less than an hour still to play across the tie, Celtic somehow found themselves on the wrong end of a 5-4 aggregate defeat to LASK. A place in the league phase was theirs to lose - and they lost it spectacularly, with individual mistakes, questionable decisions and a team that appeared to run out of answers when the pressure mounted.

The fallout will inevitably focus on Martin O'Neill, who took responsibility for the defeat afterwards. But this feels like a much bigger failure than one manager or one night. It raises questions about the squad Celtic have assembled, the decisions made in the transfer market and whether the club were truly prepared for their biggest test of the season.

O'Neill took full responsibility. But the truth is they are all to blame. Should the Celtic players be blowing a four-goal lead with less than an hour to play? No.

Did O'Neill make the right subs? Probably not - the team was severely weakened with every change and then, similar to Thomas Tuchel's England against Argentina, they were left with no attacking options when the inevitable happened.

But were Celtic fully prepared for this qualifier, compared to last season? They were certainly more prepared.

The signings of Kasper Hogh, Camilo Duran, Mika Baur and Haissem Hassan cost around £32m. They seem to have improved the squad. The starting line-up is stronger. But there were still gaping holes that needed filled.

Celtic knew Arne Engels was likely to leave, but weren't able to replace him in time for LASK. They knew Kieran Tierney needed cover, but they still haven't brought in a back-up left-back. Alistair Johnston's injury was a late blow, but they perhaps should've been ready with a replacement as he was close to leaving before his injury. So, while good signings have been made, they were not fully prepared for this tie.

For a Celtic team to finish a Champions League tie with likes of Dane Murray, Liam Scales, Anthony Ralston and Luke McCowan on the field suggests how threadbare they still are.

Also, it could be argued that postponing their Scottish Premiership match with St Johnstone at the weekend was a mistake, given how dead on their feet the team looked in the second half and in extra time in Austria. Some of them could've done with the extra minutes at the weekend.

Missing out on the Champions League could have huge consequences for Celtic in the last week of the transfer window. Celtic would've been guaranteed another £40m from Europe's premier competition.