The head of the Italian footballers' union (AIC) said that four weeks of full training is needed before Serie A can re-start without a serious risk of injury to the players.
Italian teams began training after the coronavirus stoppage on May 4, however players were only allowed to train individually and respecting social distancing rules. Full group training sessions will only be allowed from Wednesday.
The government's ban on sporting events lasts until June 14 and it is due to decide if and when Serie A can re-start on May 28.
"We shouldn't be talking about setting dates if we want to be able to get off to a good start," AIC president Damiano Tommasi told the Gazzetta dello Sport.
"Other sports need about six weeks. We need at least four weeks before we resume the championship," he said. "Everyone wants to get back to doing their job, but when training starts again we have to start this calculation."
He added: "Above all, we need to be careful and we need to be certain from a medical point of view."
(Writing by Brian Homewood; Editing by Toby Davis)
