Nacional defender Juan Izquierdo has died after collapsing on the pitch during a Copa Libertadores match earlier this month with an irregular heartbeat.
The 27-year-old Uruguayan suffered a cardiac arrest after collapsing during Nacional's game against Sao Paulo on 22 August.
Izquierdo had been receiving treatment at the Albert Einstein Hospital in Sao Paulo and Nacional initially described his condition as 'stable'.
However, his condition worsened in recent days.
“It is with the deepest sorrow and shock in our hearts that the Club Nacional announces the death of our beloved player Juan Izquierdo,” his Uruguayan side posted on X.
“We express our most sincere condolences to his family, friends, colleagues and loved ones. All of Nacional is in mourning for his irreparable loss.”
On hearing the news, a spokesperson for Brazilian side Sao Paulo said it was a “sad day for football”.
Inter Miami striker Luis Suarez said: "Pain, sadness, it is hard to explain. May he rest in peace. I wish a lot of strength for his family and friends."
Izquierdo was put on a ventilator on Sunday and had been under neurological care since Monday.
The defender was a half-time substitute for former Liverpool defender Sebastian Coates during his side's match with Sao Paulo.
He collapsed in the 84th minute and was not in contact with any other player at the time of the collapse.
Izquierdo received medical treatment on the pitch and was rushed to an intensive care unit shortly afterwards.
Uruguay's first and second division leagues were postponed at the weekend following Izquiedro's collapse.
According to Spanish newspaper El Pais, external, Izquierdo's wife gave birth to the couple's second child ten days ago.
Izquierdo had no known heart condition before his collapse.