Any idea what could be torn in my shoulder?

I dove to catch a ball and landed with my shoulder overhead and noticed a little discomfort. After playing 2 baseball games the pain got worse and worse and by the end of the second game I couldn't lift my arm from my side. It's been 2 weeks since then and it has got better since then but has kind of stopped improving but I should be having an MRI or MRA soon. The doctor said he thinks it is either my rotator cuff or labrum. In a way it feels like my anterior deltoid. I can lift my arm to the side with only small amounts of discomfort but to the front with my bicept facing up if I try and lift my arm it hurts terribly and worse if I lift it to the front with my bicept facing up and try to rotate it back like I'm going to throw a baseball. Any ideas on what this could be?