McCarthy was struck on the head by a ball hit by the Angels' Erick Aybar during a game Wednesday in Oakland. The A's announced the surgery in a statement Thursday and said McCarthy was "alert, awake and resting comfortably."
According to the statement, McCarthy was diagnosed with the injuries in a CT scan Wednesday afternoon. In the evening, after a second CT scan and medical examination, surgery was performed "to relieve pressure from McCarthy's head," the statement said.
In a two-hour procedure starting at about 9 p.m., neurosurgeons drained blood from McCarthy's head and stabilized the skull fracture, according to the statement. A CT scan Thursday afternoon showed the bleeding had subsided and McCarthy's condition had improved.
"Our first concern is Brandon's health, and we are heartened to learn he has shown progress in his recovery after surgery," A's General Manager Billy Beane said in the statement. "We are glad to report he is stable, awake and alert. ... Brandon remains in everyone's thoughts as we wish him a speedy recovery."
McCarthy's wife, Amanda, posted this tweet: "Again thank you for the thoughts and prayers, they are not going unnoticed. He has the best fans."