Sakura swallowed roughly when he placed her hand on the stump. It wasn't that she was uncomfortable touching something that needed to be fixed, she just wasn't used to being able to freely touch him. Especially in this form, at this time, it felt different but she didn't know why.
Nodding and forcing on a more professional demeanor, Sakura prodded the area gently with her fingers, trying to understand just what needed to be done to regrow this section of his wing. He was just another person who needed her help... nothing more or less.
A few long moments later she let go and nodded again, not really looking at his face. "I can do it."