It's not uncommon for you to sit in the stands and watch Oikawa train for a while before he walks you home. That day, however, he was pushing his limits more than usual, serving the ball trying to replicate the play he made in the last game, and failing. Every time the ball falls out of line or hits the net, he snorts, groans and throws another ball up, jumping to hit it at the angle he wants. You were getting worried, but you knew there was no point in getting his attention right now, so you just sat there and watched him. His eyes widened as the ball went in a strange direction. You swear you heard a crack and then Oikawa fell, a grunt of pain escaping his lips as realization slowly hit him, making his eyes water. The knee injury, the one he should be careful not to get worse.