The Portuguese star’s 2021 transfer was a sliding doors moment (Pictures: Getty)

Manchester United’s decision to re-sign Cristiano Ronaldo last year has had repercussions they could not have imagined, with the deal even impacting Pep Guardiola’s decision to extend his stay at rivals Manchester City.

Back in the summer of 2021, the Premier League champions were in need of more firepower up top and after failing to prise Harry Kane away from Tottenham they were suddenly – and unexpectedly – presented with the opportunity to sign Ronaldo.

The Portuguese star was pushing to leave Juventus and his agent, Jorge Mendes, held talks with City bosses over what would have been a controversial move to the Etihad.

In his much-discussed interview with Piers Morgan last week, Ronaldo confirmed that a move to City had been ‘close’ only for Sir Alex Ferguson and United to make a last-minute intervention.

‘It was something they spoke a lot about and Guardiola said two weeks ago that they tried hard to have me,’ said the 37-year-old during his TalkTV interview.

‘But as you know, my history with Manchester United… your heart, your feeling, the history that you had before makes the difference and, of course, Sir Alex Ferguson. It was a conscious decision because [my] heart was speaking loud.

‘I think it was key, it was the difference in that moment. But I could not be loyal and also say Manchester City was not close. But I think I did a conscious decision and I don’t regret [it]. As I mentioned before, Sir Alex Ferguson was the key.

Ronaldo’s United return has ended prematurely and on very bad terms (Getty)

‘He said it was impossible to go to Manchester City. I said “Ok boss”. I took the decision and it was conscious. It was a good decision.

‘Nobody expected [it]. Things changed around in 72 hours. They spoke, not only Manchester City, but other clubs too spoke about my name, that I will change Juventus for another club. But Manchester United was there in that pot of teams, but they surprised everybody, even me.’

But now The Athletic have revealed that Guardiola was not at all keen on the idea of signing Ronaldo and United’s late swoop could have inadvertently kept the Spaniard at the Etihad until 2025.

It is claimed that key staff at City, including Guardiola and his assistant Juanma Lillo, had significant doubts about how the five-time Ballon d’Or winner would fit into the team.

Although the reigning champions had a clear need for a goalscorer up top, Guardiola was not sold on Ronaldo and discussions with Mendes were led by the club’s executives.

Incredibly, it is even suggested that senior figures at City felt Guardiola was so against the move that he would not have seen out his previous contract – which ran until 2023 – had Ronaldo joined the club, let alone signed an extension until 2025.

Instead, City kept their powder dry for a year before landing Erling Haaland in the summer transfer window just gone, with the Norwegian’s impact playing a big role in Guardiola’s decision to continue at the Etihad for three more years.

Ronaldo’s return to United, meanwhile, has ended up backfiring spectacularly; although he was the club’s topscorer in a disappointing campaign last season, he netted just three times this season and had his contract terminated after his explosive interview with Morgan.

MORE : Chelsea’s stance on signing free agent Cristiano Ronaldo after Manchester United exit

MORE : Manchester United keen on signing striker in January after Cristiano Ronaldo exit

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The Portuguese star’s 2021 transfer was a sliding doors moment for both clubs.