Neil Lennon's Celtic future appears to be under serious threat following Sunday's 2-0 defeat by Ross County.
Lennon acknowledged time was running out for him to turn around Celtic's fortunes after his team suffered a fifth defeat during a 10-match spell in which they have only won twice.
The Betfred Cup loss sparked ugly scenes outside Celtic Park as hundreds of fans gathered to vent their fury.
Fans demanded Lennon's exit while a large number of police officers formed a human shield as the players exited in convoy.
The club said some players were left "shaken" after being targeted by missiles while police said two of their officers had been injured amid the protests. Footage showed some fans kicking down and throwing barriers.
Lennon could hear fans calling for him to depart as he walked into the post-match media conference and knew the result would cast doubt on his future despite getting the backing of majority shareholder Dermot Desmond and Peter Lawwell during a Zoom call on Friday.
A first defeat in 36 domestic cup ties would not have sparked anger on its own but it came on top of a poor European campaign and, crucially, a slump in league form.
A defeat by Rangers with an under-strength team was followed by draws with Aberdeen and Hibernian in a four-game spell.
And a growing band of fans fear Lennon cannot rescue their attempt to clinch a record 10 consecutive titles with the deficit on Rangers 11 points, albeit with two games in hand.
Lennon said after a fourth consecutive home defeat: "I've been here long enough to know that for some reason we are lacking that bit of oomph.
"You know what, it's not just this one – for the majority of the season we haven't played the football we are capable of.
"I hope I'm here to turn things around because that's what I want to do as quickly as possible. But obviously the results don't help those chances."
Ryan Christie's press conference was cut short as Celtic officials rushed to get him and his team-mates out of the stadium as a police helicopter circled over the protesters.
Before he was ushered away, Christie said: "I think the most important thing that everybody needs to know is that we still care.
"When you go on a run like this, people automatically say 'they don't care for the club' or 'they're not trying their best', whereas every single person out on that pitch was absolutely desperate to get a result to put things right.
"That's why it is so frustrating when people do say that we're not caring or we're not trying our best.
"Nobody would be at this club or would have done so well in their professional career if they didn't have that attitude going into every single game.
"But it's hard, everyone is hurting. We hurt as much as them.
"It must be horrendous for them sitting at home watching us, the team they love to see win every week.
"It's been near perfection over the last however many years, so when a run like this comes along it is a real shock to the system."