The Portuguese superstar was the 18-yard box predator, the finisher, the presence the champions needed to go again and stay ahead of the rest.
It was lunchtime on August 27 when a clearly shellshocked Guardiola faced the press, his plans in tatters.
Ole Gunnar Solskjaer is hopeful Cristiano Ronaldo can deliver once more against Manchester City
Pep Guardiola thought his club was going to land Ronaldo in the summerCredit: Getty
Sergio Aguero was gone, the painful battle to land Harry Kane had been lost, now, 15 minutes before he blinked into the lights at the Etihad Campus media suite, Guardiola was told Cristiano Ronaldo would not be wearing blue this season.
He was back at Old Trafford.
The contracts had been drawn up at City awaiting his signature.
Despite suggestions to the contrary, it was that close and Ronaldo was going to the Etihad before United and Sir Alex Ferguson’s late intervention, which pulled on his heartstrings and brought him home.
Ronaldo’s agent Jorge Mendes had told Txiki Begiristain the news shortly before it leaked out anywhere else — and in turn City’s Director of Football made sure the message got to Guardiola before he faced the media.
In Ole Gunnar Solskjaer’s press conference — minutes before Guardiola’s — the United manager could barely control his excitement and was particularly bullish about their chances of getting Ronaldo.
And why not?
The striker might be 36 now but he has nine goals in 11 games and has been a massive positive influence on and off the pitch.
Indeed, Solskjaer is at a loss as to why some people have called Ronnie’s return a backward step.
He said: “He’s one of the best players that has ever walked on this planet and his impact on and off the pitch has been absolutely immense.
“How people can say that is a negative? I can’t see that one. He scores goals, works for his team, and is a top, top pro.”
Still, could he imagine the feeling today if Ronaldo was lined up in a City shirt, back at Old Trafford?
Solskjaer countered: “The good thing is that would never happen and there is no chance of that happening.
“I am happy he is wearing the red and hopefully he can be the difference again.”
Of course, Manchester City still play wonderful football even without Ronaldo — they still create, they still score.
They have 20 goals in the league to United’s 19 and 41 in all competitions compared to their neighbours’ 27. So it’s not as if the champions are struggling overall. But six times this season they have failed to hit the back of the net.
That run of goalless games has cost them the Community Shield, their proud record in the League Cup, three points in their Champions League group and TEN points in the Premier League.
They looked particularly impotent in their last league outing, a 2-0 home defeat to Crystal Palace in which Wilfried Zaha provided a masterclass as the lone front man.
They just do not have that goalscoring predator like Ronaldo.
Or even like Edinson Cavani — and City could be facing both of them today.
Just look at how the pair linked up at Spurs in United’s 3-0 win last Saturday, pulling the home defence this way and that.
Solskjaer said: “Those two players are two of the best centre-forwards there have been in world football in the last 15 or 20 years. They have a lot of respect for each other. They work well off each other.
“We have not been able to play them together for too many games.
“That’s something we hope to see more often and it will blossom.”
Ronaldo is not only keeping United in the Champions League but in touching distance in the Premier League.
Win today and they will be level on points with City — and in the top four at the end of this round of matches if West Ham fail to get at least a point at home to Liverpool.
Of course, it could be that Ronaldo is the one who loses out in the long run if his dream was to add another league title and sixth Champions League to his impressive CV.
After all he is a winner and, for him, progress is not second best.
There is little doubt there is more chance of adding to his array of silverware with City, given the rollercoaster ride that United are on.
But would it have been as special for him pulling on that blue shirt today?
One manager wishes it could have been, another is glad it wasn’t.
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