Front Shoulder Opening up too soon

Lately i’ve noticed a decrease in my velocity (about 4-5 mph) and my shoulder had started to bother me when i pitched. While doing my towel drills, i noticed that i was flying open with my front shoulder. When i worked to stay closed it seemed to take the pressure off my shoulder. I haven’t pitched yet, but is it likely that coming open too soon had zapped my velocity and put undue pressure on my shoulder?

Opening up early can certainly rob velocity and put more stress on your arm. What adjustment did you make to work to stay closed?

Besides mentally telling myself to stay closed with my upper body, i tryed to reach with my glovehand more out towards the 3rd base side of home plate and pull it directly in

Don’t pull your glove. Once you stick it out front, leave it there. As your shoulders rotate, your glove elbow should tuck down to your side - maybe a little in front of your torso. Your glove shoulder turn over so the pocket faces your chest or face. You should then bring your chest to your glove.

And if your glove is out front at foot plant and doesn’t vacate that position before foot plant, then you will have the timing you need to delay shoulder rotation until the hips have rotated.