Celtic manager Martin O’Neill admitted Tuesday’s defeat to LASK ranked as one of his most painful nights at the club as their Champions League hopes went up in smoke during a disastrous second leg in Austria.

Callum McGregor put his team 4-0 up on aggregate in the play-off when he struck from 18 yards in the 21st minute, but they went on to lose 5-1 on the night after extra-time (5-4 on aggregate).

Defeat sends Celtic into the Europa League and delivers a damaging financial blow that will cost the club at least £20m.

“I would say absolutely, yes,” O’Neill said when asked if it was one of his worst experiences in the dugout.

“I’d put it down before the disappointment of losing the UEFA Cup final in 2003, but it’s so, so disappointing.

“We should have been out of sight by half-time. We scored a goal, which was great, we missed two great, great opportunities. And then we give them a lifeline just before half-time and then one just after it. And they come roaring back.

“And obviously we conceded, from our viewpoint, not good goals at all. But that’s my team and that’s my responsibility.

“I’m disappointed that we’ve conceded the goals in the manner which we did.”

When asked whether his squad was strong enough, O’Neill said: “These are tough games. And it might only be a Champions League qualifying game, but it felt like a Champions League game. I thought they were a fine side.

“But that doesn’t matter. We should have been able to have seen it through. And we didn’t do. Talking about the squad, that’s for another day.”

The LASK players celebrate at full time during a UEFA Champions League Play-Off Round Second Leg match between LASK and Celtic at Oberosterreich Arena, on August 25, 2026, in Linz, Austria
LASK players celebrate with their supporters at full-time

Celtic captain McGregor accepted there were no excuses for the players.

“We got what we deserved,” McGregor told Amazon Prime. “I thought we were so passive. All night. We actually looked scared to go and win the game, and when you are 3-0 up it’s psychological.

“To be honest I didn’t think we were that good in the first leg either. We scored at good times and kind of got away with it. You go 3-0 and you think you’ve got a real chance but when you play like that you can’t have any excuse whatsoever.

“We have to suck it up, apologise to the supporters and the club because there is no way that we should lose that game.

“We’ve got to stick together, we’ve got to suck it up, and now you’ll see what kind of characters are in there.”

McGregor admitted there was a “nervousness” about Celtic due to what was at stake but the 33-year-old added: “When you play like that and you’re so passive and you go 1-0 up in the game and it still doesn’t settle you, then you can’t have any excuse, and that’s on us.”

Defeat is the latest in a string of Champions League qualifying failures and Celtic’s slow start to the transfer window will again come under scrutiny.

When asked if it could be levelled that the squad was not ready or strong enough this time, McGregor paused and said: “I guess not, no. Everyone’s happy for two or three weeks and then you fall at a big hurdle, these questions are going to get asked.

“It’s as much on the players as anything else to be honest. You can’t lose that game by such a big margin and then start looking for excuses elsewhere. We have to accept that.”