Marquinhos revealed he suffered from diarrhoea and vomiting before rising to the "very complicated" challenge of marking Lionel Messi in Brazil's Copa America semi-final victory over Argentina.
The Paris Saint-Germain defender lasted 64 minutes of the match in Belo Horizonte despite being hit with a virus and, by the time Miranda replaced him, the Selecao were 1-0 up courtesy of Gabriel Jesus' first-half opener.
Roberto Firmino doubled Brazil's lead seven minutes after Marquinhos' departure and head coach Tite saw his back four restrict Argentina's front three of Lautaro Martinez, Sergio Aguero and Messi – although the latter two hit crossbar and post respectively.
Marquinhos hailed Messi's performance as "inspired" but conceded keeping tabs on the Barcelona talisman was a struggle.
"It was not easy, no," he told reporters. "He was on inspired [form that] night. Not only him, as the Argentine team made a great game.
"It was very difficult, but I think the team managed to cancel out the attacks of Argentina well.
"The ones we could not [cancel out] had some lucky chances, with balls hitting the post and Alisson made some great saves. That makes a strong and solid team."
Marquinhos said he received treatment at the stadium medical facility after the game, which saw Brazil progress to the Copa America final for the first time since 2007.
Brazil will play Peru in Sunday's final and the centre-back will hope he can stay fit and healthy as his team-mates aim to lift the trophy for the ninth time.
Describing his illness, Marquinhos added: "On the day of the game, I ended up [suffering from] a virus and I spent the day at the hotel.
"[It was] very complicated. [I had] diarrhoea and vomiting, I still managed to play a little, but with the effort it got worse [during the] game."
"After the game, it ended up getting worse too. I had a fever and I ended up having to go to the stadium infirmary. But I managed to get an injection and I feel better."