City won the first leg of their Champions League semi-final on Tuesday night and will now head to the Bernabeu next Wednesday with a one-goal advantage.
However, City were dealt a blow in the first-half when John Stones, who was covering at right-back, picked up an injury and had to be replaced by Fernandinho.
The Brazilian has mainly operated as a defensive midfielder throughout his career and has hardly ever featured at right-back.
Speaking after the match, his manager Guardiola believed Fernandinho took the full-back role in his stride despite the City man failing to challenge Real’s Vinicius Junior before the forward made it 3-2.
He said: ‘Fernandinho never do it before (play right-back), only once in the first or second season (since I am here).
‘It’s not easy to control Vinicius because he is an outstanding player. But he did everything that’s why Fernandinho is such an important player. I knew it, he would perform well.’
City are suffering a crisis in the full-back positions with the likes of Kyle Walker and Joao Cancelo out injured.
Fernandinho has become a popular figure at City since joining the club in 2013 and has been a mainstay in the team for much of their success in the last decade.
However, in the last year, the 36-year-old has lost his starting place to Rodri and, this month, confirmed that he would be leaving the Manchester club at the end of the season.
It is expected Fernandinho will head back to Brazil to see out the rest of his career.
Before then, the player is aiming to make a second successive Champions League final after City lost to Chelsea in European football’s showpiece last year.
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