SERRATUS ANTERIOR - Pain at Lower End of Shoulder Blade

Had an injury from deep massage on thoracic nerve, which resulted in winged scapula, 7 years ago.

Six months after, the injury recovered and scapula winged only slightly ever since.

However, later, I started feeling pain on the lower end of shoulder blade after light training at the gym. Likewise, I feel pain t same location when lifting a weight at home.

The pain is usually a heavy filling or burning feeling.

I keep fit, but pain had prevented me from normal training.

Do you suggest strengthening exercises for serratus anterior?

Or should I try to limit the stress on serratus anterior by strengthening other the upper back muscles?