Kieran Crowley had been due to unveil his 33-man squad on Thursday but will now name it on August 22nd, the Italian federation (FIR) announced.
No reason was given for the delay but it should allow Crowley to assess players who were injured during the 33-17 defeat to Ireland in Dublin.
Saracens prop Marco Riccioni was substituted after just 10 minutes having taken a knock to the knee and Gloucester scrum-half Stephen Varney went off after half-time with a left shoulder problem.
"Riccioni and Varney will undergo tests again in the coming days to understand the evolution of their injury and duration of their absence," FIR said Monday.
In addition, centre Tommaso Menoncello, who scored Italy's second try in Dublin, also has a left shoulder problem, while Treviso teammates Paolo Odogwu and Manuel Zuliani have to come through concussion protocols.
Italy have yet to reach a World Cup quarter-final and their chances of doing so this time look slim.
They have been drawn in Group A alongside hosts France, New Zealand, Namibia and Uruguay.
They begin their campaign against Namibia in Saint-Etienne on September 9th.
