I'm going to add something that I'm sure will get push back. It's situational, but I caution about getting an MRI too quickly. My son had back problems that sidelined him from the mound for the first half of his senior season. Doctor sent him for an MRI. They found three bulging discs, but concluded none of them were in a place that would have caused the pain he was feeling. After closely comparing video from before the pain and after, I discovered a mechanical change in his delivery. Fixing that completely relieved him of the pain - never been a problem since. Great, huh?
Well move ahead a year and he's become a draft prospect. Several clubs interested and talking somewhere between the 11th and 20th rounds. However, ALL of them wanted a copy of that MRI. Boom. Suddenly, if they wanted him at all, it was lower rounds for much smaller bonus offers.
Almost all ball players, if you get an MRI, are going to show damage to shoulders - it's just what comes with the territory. I'm not saying don't get an MRI. I'm just saying I think sometimes people jump immediately to an MRI too early when it may not be the best idea or necessary.