Former Argentina striker Mario Kempes reportedly had six bypasses during heart surgery in the United States on Tuesday.
The 60-year-old, who scored 20 goals in 43 matches for his nation, is believed to have recently told the press in his homeland that he required an operation due to his 'clogged arteries'.
According to ESPN, Kempes was put in intensive care following surgery in Connecticut earlier this week.
The former footballer, who now works as a commentator for ESPN, became top scorer for Argentina with six goals when his nation won the World Cup in 1978.