Serie A will remain suspended until at least June 14, the Italian Football Federation (FIGC) has confirmed.
The Italian top flight has been on hold since March 9 because of the coronavirus pandemic.
It had been hoped it would be clear to resume on June 13, with clubs back in team training on Monday.
However, the league will now not be able to restart until June 15 at the earliest.
The FIGC's decision is in alignment with that of the Italian government, with a prime ministerial decree suspending "sporting events and competitions of all types and disciplines, in public or private places" until June 14 as part of "urgent measures to contain the contagion throughout the national territory".
There have been nearly 226,000 confirmed cases of COVID-19 in Italy with over 32,000 deaths.
Italy recorded 99 new deaths on Monday, its lowest daily toll since early March.
Defending champions Juventus were a point clear of Lazio at the top of the table when the season was brought to a halt.