Roger, sorry I didn't give you enough to go on. I'll try to dump everything about the situation I can think of here. Sorry if I ramble.
Yes, this was his first pitching outing in a game after about seven weeks of rest. His team has been focusing on mainly winter conditioning with some mild throwing. Pitchers have been doing bullpens about two times a week for the last three weeks or so.
His first game back last Wednesday, he pitched four innings. I didn't keep his pitch count because an official scorer was used in the game. I will be keeping his pitch count from here on out with a pitch counter regardless.
He throws mainly four-seam, two-seam, circle-change, and sliders. He said he was very conservative with his sliders and that his arm pain occurred before he threw his first slider. I don't condone him using his slider, nor does his pitching coach. But he likes to use it as his out pitch when he feels he can bewilder the batter.
He's still pitching at 50 ft. He hasn't moved up, but his velocity has improved a good bit from growth and rest. He throws with a low 3/4 arm slot. He swims. He said his arm still had discomfort swimming all strokes expect breast on Monday, so we're halting that activity in the meantime while he ice and rest his arm.
He had a game last night where he just played first. He was very gentle with his arm and said he had no discomfort at all.
Finally, what I am referring to by the top side of the arm is if you hold your arm straight out with the back of your first pointing straight up the pain would be above and below the elbow joint not in the joint. The general consensus was his forearm was dipping below 90 degrees causing his arm to drag and putting excess strain on the arm. Not sure if that's the case. Another kid on our team had the same issue last night, which I thought was odd.