Marcelo is sent off in tears after his tackle leaves opponent's knee dislocated

An Argentinos Juniors defender suffered a full dislocation of his left knee on Tuesday during a Copa Libertadores match in Buenos Aires.

Luciano Sanchez, 29, suffered the serious injury after a challenge by veteran left-back Marcelo, now playing for Brazil's Fluminense. His teammates initially believed he had broken his leg, but a medical report published by the club said it was a full dislocation.

The former Real Madrid player was sent off in tears as the Argentinian screamed on the pitch, surrounded by concerned players on both teams. The incident took place in the 56th minute of the match, which finished 1-1.

Local media say doctors at the Sanatorio Finochietto hospital estimated Sanchez's recovery time between eight and 12 months due to the incident.

'I lived a very tough moment on the pitch today,' Marcelo said on social media. 'With no intention I injured a fellow footballer. I want to wish you the best possible recovery, Luciano Sanchez.'

*GRAPHIC CONTENT WARNING*

Argentinos Juniors thanked the Brazilian club and the footballer for their concern for Sánchez.

'We are rivals, not enemies,' the Argentinian club said.

Fluminense coach Fernando Diniz, who is also Brazil's national team coach until the middle of next year, said in a press conference that Marcelo did not deserve to be sent off and called the incident 'an unfortunate event.'

Gabriel Avalos opened the scoring with a volley for the hosts in the 14th minute of the first leg of the round-of-16 match.

Argentinos later saw its goalkeeper Alexis Martin Arias sent off in the 76th minute, and be replaced by substitute midfielder Luciano Heredia until the end of the match.

Fluminense took advantage of the opportunity and equalized with Samuel Xavier in the 87th minute from long range.

The teams will play again next Tuesday at the Maracana Stadium for a place in the quarterfinals.