McCarthy was hurt Sept. 5 after a line shot off the bat of the Los Angeles Angels' Erick Aybar hit him in the head. He was initially taken from the Oakland-Alameda County Coliseum to Alta Bates Summit Medical Center in Oakland, where tests revealed an epidural hemorrhage, brain contusion and a skull fracture.
He was later transferred to the California Pacific Medical Campus in San Francisco, where surgery was performed to relieve the pressure in his head.
"It's times like these when you realize you have an extended family, and feel so fortunate," McCarthy said in a statement. "Now we look forward to continuing the healing process, and returning to baseball and our normal lives in the weeks and months ahead. Go A's!"
The right-hander had compiled an 8-6 record with a 3.24 ERA over 18 starts for Oakland this season.