Milan confirmed Alex sustained head trauma when he was knocked unconscious during the 3-1 win over Lazio.
The defender was out cold after an accidental collision with his own goalkeeper Gianluigi Donnarumma, getting a knee to the side of the head.
He was clearly unconscious before even hitting the ground and landed very heavily.
Stretchered off, the Brazilian regained consciousness in the locker room before he was taken to the local hospital for tests.
Milan Channel confirmed Alex suffered head trauma and could well be kept in the Policlinico Gemelli overnight for observation.
CEO Adriano Galliani accompanied Alex to the hospital.