Diego Maradona had surgery on his right knee, the first of two procedures recommended by his doctors.
Maradona's attorney Matías Morla said the retired Argentine soccer great underwent the procedure on Wednesday at the Olivos private clinic in Buenos Aires.
The 58-year-old Maradona resigned as coach of Mexico's second-division team Dorados de Sinaloa in the middle of June.
His doctors told him he needed knee and shoulder surgeries to keep working.
The 1986 World Cup champion, who has a long medical history, suffers from severe arthritis in both his knees.
Three months ago, Maradona had an operation to stop a stomach bleed detected during a routine check-up.
Morla said Maradona has several offers to coach again after he finishes his medical treatment.