There have been many major leaguers who have had the yips trying to throw the ball. Dale Murphy was the best young catching prospect in the country and started throwing balls into CF. The made him and outfielder.
Mike Ivie was the first player chosen in the draft years ago and got so paranoid about throwing the ball back to the pitcher that he quit. He came back a little later and played 1st base and then quit again do to fear of flying.
Mackey Sasser got so bad, he used to pump three times and then throw the ball back to the pitcher.
Chuck Knobloch played 2nd and got to the point that he could not throw the ball to 1st.
Steve Sax had the same problem, and like Tommy John surgery, they called the yips in the throw Steve Sax disease.
Steve Blass was a fine pitcher for the Pirates and showed up one spring and started throwing the ball off the back stop. He retired that year.
Sax finally got where he could throw ok, and Murphy threw fine from the OF, but the others never did fix the problem.
I saw a picture in the paper of Knobloch one day, and he was trying to throw the ball and he had a death grip on it and was gripping it with all four fingers like it was a grenade.
My answer to fixing the problem......I have no idea.