Deep in the bowels of the Estadio da Luz, Martin O’Neill took his seat in his media conference, cleared his throat, and tried to pick the bones out of another chastening night in Europe.

The language and tone used by O’Neill didn’t really square with a team who had just been hammered 4-1 by Benfica and now sit without any points after their opening two matches in the Europa League.

Nor did it really tally with the reality of what happened on a night when Celtic folded like a pack of cards during a dismal first half and were 3-0 down after 36 minutes in Lisbon.

O’Neill insisted that he took solace from his team’s performance in the second half and encouragement from the fact they fought back and tried to make a game of it.

‘We could have capitulated, but I thought in the second half we were terrific,’ claimed O’Neill. ‘We created chance after chance. It’s not bravado on my part, I genuinely do believe we can still qualify.’

Granted, Celtic were better in the second half. That much was true. But it wasn’t an especially high bar given how atrocious they had been in the opening 45 minutes.

O’Neill sounded like a man clutching at straws, desperately trying to put a positive spin on what had been another damaging night in Europe.

Whether or not he truly believes Celtic were ‘terrific’, only he will know. But the fact he chose to say it publicly only demonstrated how standards have fallen.

This is a manager who once elevated this club to the most extraordinary heights in Europe, now reduced to finding comfort in a belated response from his players after the contest had already been lost.

Benfica were three goals up by half-time. Jhon Duran converted a fifth-minute penalty after Dane Murray’s clumsy foul, Alexander Bah was left unmarked to make it two, and Duran added a third before the break.

Celtic’s defending was soft, reactive and all too familiar. Only then, with the game effectively over, did O’Neill’s side begin to play with any real intensity or purpose.

Camilo Duran headed a consolation just after the hour and struck a post. Substitutes offered energy. Chances came and went.

Having taken their foot off the gas, Benfica still scored a fourth late on through Vangelis Pavlidis. The final score flattered the visitors only in the sense that it could have been much, much worse.

Former Celtic striker Chris Sutton branded his old club ‘flat-track bullies’. The contrast between those words and those of O’Neill were stark and instructive.

It is easy to start playing when you are already three goals down. The pressure has eased off. Benfica were coasting. The fear of further embarrassment is replaced by the freedom to swing.

The simple reality is that Celtic are yet to win a big match this season. Both meetings with Rangers ended in defeat.

The European campaign opened with a home loss to Ferencvaros and has now continued with this heavy defeat in Portugal.

They have conceded the most goals of any team in the Europa League so far this season. In their last three European matches taking it back to LASK Linz, they have shipped 12 goals.

Most damningly for O’Neill and his players, every high-stakes fixture this season has produced broadly the same outcome.

The league table may still offer some insulation in the sense that Celtic are still top, but the character of the performances in the games that matter most does not.

Standards have fallen dramatically. That is not hyperbole. Rather, it is the measurable truth of Celtic’s recent European record and their repeated failure to deliver when the opposition is organised, technically proficient, and clinical.

O’Neill’s first tenure at Celtic was built on raising those standards. His teams were hard to beat in Europe for a reason.

They did not wait until the game was gone before deciding to compete. They did not require the opposition to take their foot off the gas before showing their quality.

This current version of Celtic under the same manager appears to have inverted that principle. They can produce moments against lesser domestic opposition, such as against Motherwell last weekend.

They can respond when the scoreline has already condemned them to defeat. What they cannot do, so far, is impose themselves when the match is still there to be won or lost.

That is the definition of a side whose standards have slipped. O’Neill’s claim that the second half was ‘terrific’ only highlights the issue.

No manager should ever seek to excuse his players and give them credit for recovering from a hole they dug themselves with basic errors.

There is a fine line in these situations between defiance and delusion. O’Neill’s words on Thursday night in Lisbon sat uncomfortably close to the latter.

Praising a second-half display that arrived only after the contest was decided risks normalising the collapse that preceded it.

It risks telling the players that the real examination starts once the damage is done rather than before it. It is fundamentally not good enough.

Sunday’s home game against Hearts is no longer just another run-of-the-mill league fixture. For O’Neill and his players, there is now real jeopardy attached to this.

Hearts are not at the same level as Benfica. Then again, neither were Ferencvaros. Or Rangers. Or, indeed, LASK Linz for that matter.

Celtic need a win tomorrow and they need a performance which signifies some degree of progress is being made.

Anything less will make O’Neill’s continued presence as manager increasingly difficult to defend. The 74-year-old would not be human if he didn’t have cause to reflect on his decision to stay on this season.

He remains a figure of genuine stature at Celtic Park. Only Jock Stein stands above him in the pantheon of the club’s all-time greatest managers.

But stature alone does not excuse results. It does not rewrite the record of repeated big-game failures this season. And it most certainly does not turn a 4-1 thrashing into some kind of positive PR spin.

O’Neill is entitled to take whatever encouragement he can from the second half in Lisbon. Managers always do.

The rest of us are entitled to notice that it only arrived once the game was gone, that Celtic remain without a win in a meaningful fixture this season, and that another failure against Hearts would leave precious little case for the defence of the current regime.

Defiance has its place. Delusion does not. Celtic and O’Neill are running out of room to tell the difference.