Teams in Serie A have been hit by a ban limiting the number of foreign players they can sign.
The new rule - brought in by the Italian Football Federation (FIGC) - means clubs can only bring in one non-EU (European Union) player each season.
The signing can only be brought in to replace another non-EU member of the squad and the new cap is a reduction from the previous level of two players.
The decision was made following Italy's shock exit from the World Cup finals in South Africa, where the reigning champions were sent home bottom of Group F.
The announcement has angered some officials of clubs in Italy, who feel the move has been made too soon.
Lega Calcio, the governing body of Serie A and B, has criticised the decision, with president Mario Beretta saying: "It won't solve anything.
"This decision leaves a bad taste in the mouth."
AC Milan president Adriano Galliani added: "This won't resolve the problems in Italian football.
"I absolutely share the position put forth by the Lega Calcio and president Beretta."