Diego Maradona was admitted to a clinic in Buenos Aires on Saturday to undergo a scheduled procedure due to stomach bleeding, according to multiple reports.
Maradona, 58, was diagnosed with a health problem in early January during routine exams performed at the same hospital in the town of Olivos.
The surgery is expected to last one hour.
He was preparing to travel to Mexico to take over the technical management of the Dorados de Sinaloa football club.
"It is bleeding due to a hernia. It is not complicated at all," a source told Reuters on Saturday, adding: "With this, he hopes to solve some of the inconveniences that he usually has."
Information from Reuters was used in this report.