Argentinos, who won their third league title in 2010, said Gorosito's assistant Jorge Borelli would be in charge for Saturday's Clausura championship visit to Independiente and Astrada would take over on Monday.
"Astrada will be the coach. In Thursday's board meeting the ex River [Plate] and [Rosario] Central trainer was chosen as successor to Nestor Gorosito," Argentinos said.
"The new coaching staff will take charge next Monday," they said on their website.
It will be the second time that Astrada follows Gorosito into a coaching job since October 2009 when he succeeded him at River, the club where both began their playing careers.
The 42-year-old Astrada, a member of Argentina's 1998 World Cup squad who has won league titles as player and coach with River, was out of work since leaving Paraguay's Cerro Porteno, whom he led to last year's Libertadores Cup semi-finals.
Gorosito, 47, handed in his resignation to Argentinos from his hospital bed on Tuesday.
He suffered multiple injuries including backbone damage in a crash in the early hours of Saturday on a highway on the outskirts of Buenos Aires and will have to remain in hospital for at least two months.
Argentinos have picked up only one point from three matches in the Clausura championship that kicked off on February 10.
