The Albert Einstein Hospital in São Paulo reports that the defender who plays for Uruguayan Nacional passed away on Tuesday evening after a cardiac arrest linked to heart rhythm disturbances.
The club writes in a statement on social media that "the entire Nacional is in mourning for this irreparable loss".
It was during the match between Nacional and São Paulo in Copa Libertadores, where Izquierdo was substituted in at halftime, that the defender then collapsed.
Izquierdo was taken by ambulance to the hospital where he was treated for several days, but his life could not be saved.
Several Uruguayan players and teammates of Izquierdo have expressed their condolences.
"Pain, sorrow, it's hard to explain. May he rest in peace. I send strength to his family and friends", says Uruguayan striker Luis Suárez.
The chairman of the Brazilian Football Association, Ednaldo Rodrigues, says that a minute of silence will precede every match organized by the association on Wednesday, reports ESPN.
Juan Izquierdo was 27 years old.