After the game, Marcelo took to social media to apologise for his part in the incident.
The 35-year-old said on Twitter: "Today, I had to experience a very difficult moment on the pitch.
“I have inadvertently injured a colleague. I want to wish you the best possible recovery, Luciano Sanchez. I send you all the strength in the world!"
Fans have since thrown their support behind Marcelo, who was visibly devastated after Sanchez’s horrific break.
One person wrote in the comments: “You are a giant and all the tricolours are proud to see you wearing the club's shirt.“We all know you didn't have the slightest intention in the bid. Soon Sanchez will be on the field again, God willing!”
Another wrote: “Sometimes things happen that you don't want and that input is one of them, it wasn't your fault. cheer up.”
A third person said, in a tweet translated from Portuguese: “Noble attitude of someone who has history and many services rendered to football. Giant, Marcelo. Good recovery for Sanchez.”Gabriel Avalos opened the scoring with a volley for Argentinos in the 14th minute of the match.
However, the hosts later saw their goalkeeper Alexis Martin Arias sent off in the 76th minute, and be replaced by substitute midfielder Luciano Heredia. Fluminense took advantage, equalising through Samuel Xavier in the 87th minute from long range.
The teams will play again next Tuesday at the Maracana for a place in the quarterfinals.
