"The best thing was to step aside," Garnero told reporters at Independiente's training complex outside the capital the day after a crushing 4-0 defeat by Banfield in the Apertura championship.
"My exit is by mutual agreement," he added after speaking to the squad. "I meet with the board of directors today and we took this decision."
Independiente general manager Cesar Luis Menotti, Argentina's 1978 World Cup-winning coach who had recommended Garnero's appointment, resigned.
Media reported that the board was anxious to bring back Americo Gallego, last season's coach who was not retained after his team narrowly missed out on the Clausura championship title.
Hector Rivoira, coach of fellow first division side Huracan, 14th with eight points from seven matches, resigned on Monday citing exhaustion. His side lost 3-0 at Gimnasia in La Plata on Friday.
Under former midfielder Garnero, who has limited coaching experience, Independiente picked up three points from three draws in seven Apertura championship matches.
The only bright spot in his brief tenure was beating equally troubled Clausura title holders Argentinos Juniors 2-1 on aggregate to qualify for the second round of the Copa Sudamericana, South America's equivalent of the Europe League.
Independiente, crowned South American champions a record seven times, last won a league title in 2002 during the first spell under Gallego, a central midfielder in Menotti's World Cup-winning side.
