The winger broke his arm in training while attempting an overhead kick, following in the line of a number of players to have suffered bizarre injuries while at the club
The injury occurred during a game of football tennis, when Piatti attempted an overhead kick and landed awkwardly.
The 23-year-old left the training field in anguish as medical staff tried to assess the scale of the injury, before leaving the facility to undergo tests that should reveal his length of absence.
Early indications suggest that the former Estudiantes man could be out for up to two months, with Piatti becoming the latest Valencia player to suffer a bizarre injury while at the club.
Ever Banega broke his fibula after failing to apply the handbrake on his car in February, while former goalkeeper Santiago Canizares severed a tendon in his foot after dropping a bottle of aftershave on it, an injury that ruled him out of the 2002 World Cup.