Celtic manager Martin O’Neill did not hide his frustration after his side suffered a damaging 2-1 defeat to Celta Vigo at Celtic Park, questioning two major refereeing decisions while admitting that his players must learn how to manage European matches more effectively.

The Hoops appeared to have given themselves a platform for victory when Mika Baur fired them ahead shortly after half-time. However, Celtic’s advantage disappeared in the closing stages as Javi Rodríguez scored twice in quick succession to complete Celta Vigo’s comeback on October 22.

O’Neill was particularly unhappy with the decision to award Celta a free-kick shortly before their equaliser. He believed Camilo Durán had been fouled moments earlier and felt Celtic were unfairly denied a decision that could have changed the course of the match.

The Celtic manager also questioned why VAR had not intervened over an earlier challenge involving Callum Osmand.

Yet while the officiating will dominate much of the post-match discussion, Celtic’s inability to protect their lead presents a more worrying problem. Another European defeat has left the Scottish champions under increasing pressure, with their manager insisting that victories are now essential if they are to keep their qualification hopes alive.

MARTIN O’NEILL TAKES AIM AT THE REFEREE AFTER CELTIC DEFEAT

O’Neill was clearly unhappy with Bulgarian referee Georgi Kabakov following the match, particularly over the sequence of events that led to Celta Vigo drawing level.

Celtic believed they should have received a free-kick after an incident involving Durán. Play continued, however, and a subsequent foul by Liam Scales gave the Spanish visitors an opportunity to threaten from a set piece.

Celta made the most of that opportunity. Javi Rodríguez rose to meet Hugo Álvarez’s delivery in the 68th minute, directing a header beyond goalkeeper Sam Johnstone to make it 1-1.

O’Neill argued that the decision immediately preceding the free-kick had gone against his team.

He explained after the match that he believed Celtic should have received a foul seconds earlier, before the referee awarded Celta the set piece that produced their equaliser.

The Celtic manager also suggested that the goal disrupted his team’s concentration. Once the visitors had levelled, they gained momentum and quickly turned a difficult situation into a winning position.

O’Neill’s frustration is understandable. Decisions around free-kicks can have significant consequences, especially when a team is defending a narrow lead late in a match.

However, there is an important distinction between believing a referee made the wrong call and proving that the decision determined the final result. Celtic still had opportunities to respond after conceding, but the team was unable to regain control.

O’NEILL QUESTIONS VAR OVER CALLUM OSMAND INCIDENT

The Durán incident was not the only decision that troubled O’Neill.

The manager also revisited a first-half challenge involving Osmand, who appeared to be pushed as he moved towards the penalty area. Celtic players appealed, but the referee did not award the foul or penalty they wanted.

According to O’Neill, officials indicated that VAR had checked the incident. He questioned what the review had been examining because he believed the contact constituted an obvious foul.

The incident added to the frustration among Celtic supporters, particularly because the match remained goalless at the time.

A decision in Celtic’s favour could potentially have created a different attacking opportunity, but it would be speculative to claim that it would necessarily have changed the outcome.

VAR reviews are governed by specific intervention criteria, and not every disputed contact leads to an on-field decision being overturned. Without the full review footage and officials’ explanation, it is difficult to reach a definitive conclusion about whether intervention was warranted.

Nevertheless, O’Neill’s comments underline the anger surrounding the decisions and the feeling within the Celtic camp that key moments did not go their way.

LIAM SCALES’ HEADER COULD HAVE CHANGED EVERYTHING

Perhaps the biggest turning point came after Celtic had taken the lead.

Baur opened the scoring in the 47th minute, giving the home supporters reason to believe their team could secure a valuable European victory.

Celtic then had an opportunity to strengthen their position when Liam Scales connected with a cross from Haissem Hassan. The defender’s header struck the crossbar rather than finding the net.

Had the effort gone in, Celtic would have moved two goals ahead and placed considerable pressure on Celta Vigo.

O’Neill acknowledged the significance of the chance, arguing that the fine margins of European football can determine whether a team celebrates a victory or leaves the pitch disappointed.

There is logic behind that assessment. A two-goal advantage would have forced Celta to take greater risks, potentially opening up spaces for Celtic to exploit on the counterattack.

But the missed opportunity also highlights a recurring challenge for teams competing in Europe: promising spells must be converted into a decisive advantage.

Celtic had worked hard to establish their lead. Failing to score a second left the door open for Celta, who continued to apply pressure and eventually found the breakthrough they needed.

The crossbar was unfortunate, but Celtic cannot rely on one missed chance to explain the defeat.

CELTIC’S THREE-MINUTE COLLAPSE IS THE BIGGER CONCERN

For all the controversy surrounding the officiating, the speed of Celta Vigo’s comeback should worry O’Neill more than any single decision.

Rodríguez equalised in the 68th minute before scoring again in the 71st. His second goal, a powerful strike from outside the penalty area, turned the contest completely around.

Within approximately three minutes, Celtic had gone from leading the match to chasing an equaliser.

That is a damaging sequence for any team, but particularly for a side attempting to rebuild confidence in European competition.

After conceding the first goal, Celtic needed to slow the game down, regain possession and restore their defensive organisation. Instead, Celta found another opening and punished the home side again.

Game management does not simply mean defending deeper when ahead. It involves recognising when the match is becoming unstable, making sensible decisions in possession, communicating effectively and preventing the opposition from building momentum.

Celtic could have responded to the equaliser by taking fewer risks temporarily, keeping the ball and forcing Celta to work for their next opportunity.

Instead, the visitors were able to capitalise on the shift in momentum.

O’Neill was right to acknowledge that his players needed to remain calmer. Refereeing decisions can be frustrating, but teams competing at European level must be capable of recovering from setbacks without allowing one goal to become two.

DID MARTIN O’NEILL WAIT TOO LONG TO MAKE CHANGES?

The defeat also raises questions about Celtic’s substitutions and whether the team needed fresh energy before Celta scored.

Celtic made their first change shortly before the hour mark when James Forrest replaced Osmand, who had gone down in discomfort. The hosts then introduced Kasper Høgh after the equaliser, followed by Oliver Sørensen and Sebastian Tounekti.

Those changes gave Celtic fresh options, but the timing inevitably invites scrutiny after such a rapid collapse.

When an opponent begins pushing a team deeper, the manager must decide whether to make an adjustment before control disappears. That could involve introducing fresh midfield legs, changing the team’s shape or adding a player capable of retaining possession under pressure.

However, substitutions should not automatically be blamed whenever a team loses. The available options, players’ fitness, tactical responsibilities and the flow of the match all influence those decisions.

The more important question is whether Celtic recognised how the contest was changing.

If the players were tiring and Celta were increasingly comfortable applying pressure, an earlier intervention might have helped. Equally, the goals themselves involved moments that the players on the pitch were responsible for managing.

O’Neill will need to review both his own decisions and the team’s execution before Celtic return to European action.

FOUR CONSECUTIVE EUROPEAN DEFEATS PUT CELTIC UNDER PRESSURE

The defeat adds to a deeply frustrating European run for Celtic.

The club’s official match report confirmed the 2-1 loss at Celtic Park, with Rodríguez scoring both goals for Celta after Baur had given the hosts the lead. The result left Celtic facing a difficult route towards qualification.

O’Neill has not abandoned hope, but his message was direct: Celtic must find a way to win European matches.

That challenge is bigger than one refereeing controversy.

Celtic need to turn competitive performances into points, improve their defensive concentration and become more efficient when opportunities arise. They also need to show greater resilience when matches take an unexpected turn.

European football often punishes small mistakes more severely than domestic competition. Opponents can exploit a poorly defended set piece, a lapse in midfield organisation or a failure to control possession during a difficult spell.

Celtic have experienced those consequences repeatedly, and the pressure will grow if they cannot respond in their remaining fixtures.

The manager’s confidence that qualification remains possible provides a reason for supporters to keep believing. But optimism alone will not be enough. Celtic need results, and the margin for error is becoming increasingly small.

CELTIC MUST STOP LETTING FRUSTRATION TAKE CONTROL

O’Neill’s criticism of the referee will appeal to supporters who felt Celtic were denied important decisions. The Osmand incident and the foul preceding Celta’s equaliser deserve examination, and the manager is entitled to explain why he believes the calls were wrong.

But Celtic cannot allow frustration to become a substitute for solutions.

Even if every disputed decision had gone in their favour, the team would still need to improve its ability to defend a lead and respond to adversity.

The most concerning aspect of the defeat was not simply that Celta equalised. It was that Celtic conceded again before they had properly recovered from the first goal.

That sequence suggests a problem with composure, defensive organisation and momentum management.

O’Neill now faces the challenge of making sure the players understand the difference between a disappointing decision and a match that is still there to be won.

Celtic’s supporters will expect a response, both in terms of results and performances. The team must show that it can handle pressure without losing its structure.

WHAT HAPPENS NEXT FOR MARTIN O’NEILL AND CELTIC?

Celtic cannot afford to dwell on the defeat for too long. Their domestic commitments provide an immediate opportunity to restore confidence, while the remaining European fixtures demand a more disciplined approach.

O’Neill will need his experienced players to lead by example, particularly when matches become tense. Keeping possession, communicating clearly and avoiding unnecessary fouls could make a significant difference in future European contests.

The attacking players must also be more clinical. Scales’ header striking the crossbar was a painful moment, but Celtic need to create and convert enough opportunities to give themselves breathing room.

Defensively, the team must find a way to remain organised when conceding. A setback should trigger a controlled response, not a period in which the opposition is allowed to attack with increasing confidence.

O’Neill has identified the need to win both at home and away if Celtic are to keep their European hopes alive. That is a demanding task, but the message leaves little room for confusion.

The debate over the officiating will continue. Ultimately, however, Celtic’s future in Europe will be decided by what happens on the pitch.

O’NEILL HAS REASON TO BE FRUSTRATED WITH THE REFEREE, BUT CELTIC’S BIGGEST TASK IS LEARNING HOW TO PROTECT A LEAD. Until the Hoops can do that consistently, even promising performances risk ending in the same familiar disappointment.