The A's released a statement saying McCarthy "is alert, awake and resting comfortably" after undergoing surgery to relieve pressure in his head.
"He is one of the biggest-respected guys in baseball. He is one of the guys I looked up to when I was in Oakland. He is unbelievable," Gonzalez said. "When the guy is healthy, he is lights-out. When you see something like that happen to him, I wish him the best. I just hope nothing happened. I hope he is OK. He is one of those guys I wish we could build a shield once in a while. It's just one of those things you dread not to happen. ... I hope he is healthy. I hope he is strong. I hope he bounces back."