Answer:
Epidural hematoma
Explanation:
Epidural hematoma is a condition of head injury where there is severe pain in the head. Bleeding occurs between the dura mater and the skull which causes extensive pain in the head. The person feels altered alertness and unconsciousness. The person also get a shocked and is unable to react for while.
In the context, a baseball player hits his head with the baseball and is astonished for a while and afterwards suffers from severe pain in the head. The player is most likely experiencing Epidural hematoma.