My son is also a 17 YO high school junior (LHP) this year who just developed "pain" in his left elbow Saturday a week ago. That day, in a "umpires clinic", he had pitched to five batters with a GO/SO/SO/SO/FO throwing 15 pitches. Afterward our team went back to our field and scrimmaged again. I don't know how much he had thrown then but he said he stopped when it started hurting. I believe it was Monday morning he called me from school asking to go have it checked out by a doctor. As coach has requested, I told him to immediately report to the coach. Coach had trainer work with him M, Tu and W with bands and he only long tossed. Thursday at practice arm was feeling good but after about four pitches he said he had such a pain he went to his knees. Trainer made appt. next morning with ortho. and was diagnosed with "elbow strain" and sent him directly downstairs to begin therapy. He said that son's pain is where you want it to be in an elbow if you have to have pain. I can't describe exactly where except on top/back. Said it would take a couple of weeks to work it out. This really worried son and me because he had only ever experienced soreness with no pain. Goes to therapy today, Wed. and Fri and M, W next week and back to ortho. 3/2. This is going to be the longest two weeks. It was hard enough when he became "pitcher only" to realize if he didn't pitch he didn't play. But now with him benched a couple of weeks, at least, it is going to be tough with today being the opening day of our preseaon tournament. We are grateful, though, that it is nothing serious at this point. I guess it was bound to happen sooner or later. I used to think it odd for all the other boys who complained of hurt arms and my son never did. Now he is right up there with them.
I'm thinking that he shouldn't have pitched again an hour or so later after having cooled down even through he only threw 15 pitches. Maybe he wasn't warmed up again properly.
Just goes to show "the Lord giveth, and the Lord taketh away". God revealed to me that His plan for my son may not be the same as "my" plan and to have faith that His plan would endure. Boy it's hard to keep my hands out of the plan, but I'll try because I know He will remove them if I don't.
Have a great day.