Serratus anterior pain when overhead pressing/chin ups

I had been doing overhead pressing and doing pull ups, and my serratus anterior ( the muscles under my chest, next to my upper abs, right side) had been aching somewhat. I didn't think of it as anything serious, but one day I felt this extremely sharp pain while overhead pressing and I decided to stop.
How do I screen for the problem and approach rehabbing it?Attachment 7382 I put a picture highlighting the area of pain.

You might first try compressing the area with a stiff ace wrap or a Velcro weightlifting belt and see if you get any relief or abatement if symptoms when doing your chin ups.