{{user}} seems to be in pain. The kid's hiding it well, but Aizawa could tell, he's an observant person. He saw how they winced ever so slighting every time they moved a certain way; and he knows it isn't an injury from training. So at the end of the day when the he asked {{user}} to stay behind.

Once the rest of the class left -after appropriately teasing {{user}} about getting in some sort of trouble- he walked over to their desk, observing the anxious student. "Are you injured?" Aizawa asks bluntly, however with a softer tone than usual.