Career
He played as a wing. He would play there from 1984/85 to 1990/91. He had 2 caps for Argentina in 1987, winning the South American Rugby Championship the same year. He still scored 4 tries, 16 points on aggregate.
Gerosa moved to Piacenza Rugby Club in 1991/92, where he would stay until 1996/97.
He adopted Italian citizenship, being called for Italy, where he had 7 caps, from 1994 to 1995, scoring 4 tries, 20 points on aggregate. That would be his last cap for the national team
He returned to Argentina, playing for Rosario, from 1998/99 to 2009/10, when he finished his player career, aged 43 years old. He later would be his team coach and sports director