I cant throw anymore...Shoulder Pain

[fordlife]

My shoulder is "messed" up somehow. But it is not affecting my lifting, in fact I am increasing in weight and my shoulders are getting bigger.

But soon as I go to throw a ball of some sort, pain immediately.

any clue?

I remember playing catch with my buddy a littler over a year ago. After about 30 minutes my shoulder started to hurt and I figured it was from not throwing for a long time. My friend who grew up playing baseball said your arm is supposed to hurt after catch not during.

Could it be my rotator cuff?

ps. Not trying to be sneaky and trying to post a link, my question is for real.