That's according to talkSPORT host Jason Cundy, who insisted City are enduring a full-blown crisis following their Champions League setback.
Guardiola's side looked to be in cruise control when Erling Haaland scored in the 53rd minute to put City up 3-0 at home against Feyenoord.
But in the space of 14 staggering minutes, Arne Slot's former side had equalised to silence the majority of the stunned Etihad crowd.
Although the 3-3 result snapped a five-game losing streak for City across all competitions, David Hancko's 89th-minute strike will have felt like a defeat for Guardiola and his troops.
Reacting on talkSPORT's Sports Bar immediately after the contest, Cundy and ex-Tottenham midfielder Jamie O'Hara couldn't believe the capitulation that had just transpired.
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"It's a stinker, that," O'Hara said.
"3-0 up? What are they doing?"
Cundy added: "Tonight, wheels have come off.
"Look, Spurs were brilliant on the weekend. City were terrible, they got turned over in the Premier League.
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"3-0 up against Feyenoord with 15 minutes to go? And you draw 3-3? Wheels have come off. That's it."
Some fans will point out City look like a completely - and not for the better - team without Ballon d'Or winner Rodri in their midfield.
However, given that Rodri tore his ACL against Arsenal in September, O'Hara wasn't having the Spaniard's absence as an excuse any more.
"It can't just be about Rodri," O'Hara said.
"We've got past that now. There's something going on at Manchester City that no-one seems to have the answer for."
Cundy then delivered a brutal dissection of just what had gone wrong for City, with plenty of warning signs presenting themselves during a 4-0 loss to Tottenham last Sunday.
"They are so open," Cundy said.
"Their press, there is no joined-up thinking. Pep has signed a new deal, which is good for City.
"But right now, this is probably going to be his biggest job ever in management to turn this around. They are a mess.
"I'm watching Man City against your lot (Tottenham) on the weekend. I'm watching Spurs bop the ball around deep in their own half. Not only that, Spurs get out, there's an overload, three versus one, on the right-hand side. How is that happening? That never happens.
"Spurs were magnificent. City, terrible. Watching tonight, they don't look comfortable at 3-0 up. How can that happen?
"The wheels have come off tonight, officially. Spurs at the weekend, they were wobbling. Tonight, the wheels have come off."
O'Hara noted that with City's dreadful run of form, 'Liverpool must be licking their lips.'
Pep Guardiola shows of his strange scratches after Manchester City's dramatic slip up against Feyenoord in the Champions League
As it stands, Premier League leaders Liverpool hold an eight-point advantage over second-placed City.
That gap could easily become 11 when Slot's current side welcome a battered and bruised City to Anfield on Sunday.
Clearly frustrated by his current form, Guardiola arrived at his post-match interview with painful-looking red scratches all over his head.
Asked in his press conference what caused the scratches, he replied: "Yeah, my finger here. My nail. I want to harm myself."
Matters could now get worse for Guardiola on Sunday if Liverpool can snag three points at Anfield.
Another defeat could lead some to boldly declare City have too much ground to catch up in the race for the Premier League title.
Should City lose to Liverpool they may end the weekend as low as fifth given Chelsea, Arsenal and Brighton are all on 22 points.
Guardiola said: "It will be a tough season for us and we have to accept it. We lost a lot of games lately, we are fragile and of course we needed a victory.
"We were playing at a good level but the first time something happened we had problems. I don't know if it is mental.
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"The first goal cannot happen and the second as well. After that we forget what happens.
"Three episodes, they didn't allow us what we needed to win for many reasons, not just in terms of qualification or get the points to go through. Other reasons. It is what it is, difficult to swallow right now."