I just looked it up and in 1993, he pitched 1 inning, allowing 3 ER on 3 walks and 2 hits. A month later he had to undergo season ending ligament surgery on his right elbow. I guess his body was too bulky and muscle-bound, and he wasn't used to the pitching motions, which caused the injury.
And about the homerun being hit off his head.... 3 days before he pitched, he was going for a fly ball and jumped at the wall to catch it. But instead of catching the ball, it hit off his head and went for a home run. That does not sound like it was a good week for Jose!