The Italy international withdrew from training on Wednesday morning after feeling discomfort in his calf, with tests on Thursday morning revealing a tear which rules him out of Saturday’s showdown.
“Giorgio Chiellini was subjected to tests following calf discomfort in yesterday’s session,” the club announced in a statement.
“The tests showed a first-degree lesion of the soleus muscle in his left leg, so the defender will not be available for the match against Barcelona.”
The news comes as a bitter blow to the Bianconeri’s treble hopes, with Chiellini a mainstay in defence as the Old Lady marched to a League and Cup double.