It has been well documented that Rafael Nadal has had his share of shoulder problems. Over the years he’s done a lot or pre-hab focused work with his Athletic Trainer to improve the function of his thoracic spine and scapular stabiliser muscles.
Watch this video to see some of the exercises that he does as part of his shoulder pre-hab.
The one I like in particular is the scapular depression/retraction drills he does on the chin up bar. This specifically targets the lower trapezius muscle as he needs this muscle to allow full scapular posterior tilt at the top of the serve.