"Atlante's management confirms Ricardo La Volpe's departure for health reasons. Tomorrow (Tuesday) we will reveal the new coach of the Colts," a club statement said on Monday.
"It's an aneurism of the abdominal aorta," La Volpe said. "I have already had studies and it requires an operation. It's nothing grave but it's a fact that I need to have an operation.
"It's the only way to be sure; my health comes first and then football," said the chain-smoking, 60-year-old Argentine, nicknamed Bigoton because of his big moustache.
La Volpe, who has spent most of his coaching career in Mexico, steered the national team to the 2003 Concacaf Gold Cup and the second round at the 2006 World Cup in Germany.
He was in his third spell at Atlante, with whom he won a league title in 1993, and leaves them in 15th place in the Clausura championship with three points from four matches.
La Volpe, a goalkeeper in Argentina's 1978 World Cup-winning squad, has also coached Boca Juniors, Velez Sarsfield and Banfield in his home country.