Fiorentina confirm Cristiano Biraghi has suffered a Grade II lesion to the collateral medial ligament in his left knee.
He sustained the injury during international duty, forcing him to miss out on Euro 2020 qualifiers against Greece and Bosnia-Herzegovina.
The left-back was released for a return to his club, where tests were performed to identify the extent of the damage.
A statement from Fiorentina confirmed he had been diagnosed with a Grade II lesion of the collateral medial ligament in the left knee.
His condition will be evaluated over the next few weeks, but surgery is probably not required.
It is hoped Biraghi will be ready to take part in pre-season training in August.