Lagging arm ad discomfort in shoulder

hi i have a friend that has not thrown in 2 years and now he started getting back into baseball recently but when he throws his arm really lags behind his shoulders. his whole body has rotated before the arm comes around and this is causing some discomfort in his shoulder, any drills to help him with his timing and to speed up this arm? thanks

I would think the hersheiser drill would be great to help this out! Drives the hips longer toward home prior to release.

Instead of looking at it as a late arm, look at it as early shoulder rotation. Then look for things that cause early shoulder rotation such as posture issues (head movement) and glove issues (dropping, pulling, flying open) and fix those.