The 38-year-old Carboni played 44 competitive matches as Valencia won the league/UEFA Cup double in 2003–04. On 23 October 2005 he became the oldest player at the age of 40 years, six months and 17 days to take the field in the Spanish league, a record previously held by Deportivo de La Coruña's Donato – he had already achieved the feat of being the oldest winner of any European club competition when he won the UEFA Cup.