Prime Minister Giuseppe Conte has announced that individual athletes can train from May 4, but team sports, including football, must wait until at least May 18.
The AIC said the decision left footballers "perplexed and surprised".
"The idea seems discriminatory, even illogical to let individual sporting disciplines enter training grounds, but not professional footballers and other athletes registered for team disciplines," the AIC, headed by former Italian international Damiano Tommasi, said in a statement.
"The rule also risks aggravating and not containing the risk.
"For professional athletes this phase of training after such a long period of enforced stop is necessary to avoid injuries and be ready to start training in groups from May 18."
Italy's 20 top-flight clubs have voted unanimously to complete the league season which has been on hold since March 9, but the final decision will be down to the government.
The government's decision had also been criticised on Tuesday by Francesco Acerbi, Lazio defender.
"I don't want to create controversy and I am also representing my teammates. I don't understand why I can't go running in a sports centre, which respects all the safety rules, but I can do it in a public park," Acerbi said in an interview with Lazio's official television station.
De Ligt, on the other hand, decided to pack his bags and go to the Netherlands with his girlfriend after telling Juventus. The defender could not take it anymore in Italy and has returned to his country until the return date is closer.
In France, Prime Minister Edouard Philippe announced Tuesday that professional football, rugby and other sports cannot resume until the end of the summer.
Italian Sports Minister Vincenzo Spadafora defended his government's cautious approach as Italy grapples with a virus which has killed over 27,000 people in the country.
"The prudence we are having concerning football is what still leaves a glimmer of hope of resuming the championship," Spadafora wrote on Facebook.
"The alternative is to do as France did, to say that football stops here.
"Everything will depend on the evolution of the health crisis and our ability between now and May 4 to respect the rules.
"If we think that from May 4 it's all over and we can resume anything without respecting the rules and take a whole series of precautions, we are wrong and we risk finding ourselves in a worse situation than before."