According to a local hospital, the death was caused "by postanoxic encephalopathy and a multiple failure of his organs caused by the prolonged cardiac arrest that provoked his admission to the hospital."
The 22-year-old Spanish international had been in a critical condition in the Virgen del Rocio hospital in Seville since he collapsed after running back toward the Sevilla goal 35 minutes into Saturday's home game against Getafe. He regained consciousness and was able to walk from the field, but doctors said that he collapsed again in the locker room and had to be given cardiac resuscitation before being taken to hospital.
"Today is one of the saddest days in the history of Sevilla Football Club," a tearful Sevilla president Jose Maria del Nido told reporters. "That diamond left foot of Antonio Puerta's has left us, that left foot that changed our lives has left us."
Sevilla, the UEFA Cup champion in 2006 and 2007, was scheduled to play two games this week. Its Champions League qualifier against AEK Athens in Greece on Tuesday was postponed, but Friday's European Super Cup against AC Milan in Monaco might still be played as a tribute to Puerta, who had one cap for Spain.
A number of prominent players have collapsed and died in recent years, most notably Cameroon's Marc-Vivien Foe, who died during the semifinals of the 2003 Confederations Cup in France.
Hungarian Miklos Feher of Benfica died in January 2004, Sao Caetano defender Serginho died in a Brazilian championship match in October 2004, and Hugo Cunha of Portuguese club Uniao Leiria died in 2005.
Only hours after Puerta's death, an English League Cup match between Nottingham Forest and Leicester City was called off at halftime after Leicester defender Clive Clarke collapsed in the locker room. The Irishman was reported to be in a stable condition in a Nottingham area hospital.
Third division Forest were leading second level Leicester, 1-0, on a goal by ex-MLS player Junior Agogo.