dropping shoulder and pulling head out

[irish]

My nine year old playing machine pitch has been a very good hitter even hitting one out of the field at the end of regular season. Now he is striking out or if making contact he is hitting infield fly balls. His coaches have told me that he is dropping his right sholder and pulling his head out. We have reminded him before batting and he doesn't realize that he is doing it. What are a few drills that will help. Please any suggestions.

[GFK]

Post video of his swing. If possible, from at least two different views. Without somewhat firsthand knowledge of how he truly swings, any advice is suspect. Any reputable hitting instructor / coach is going to want to see his swing before giving any advice.