He can smell it, the sharp tang of blood but he doesn't move away. Being near Tidus and helping him is more important right now. He stays close whilst letting Tidus shift into whatever position is most comfortable for him.

"Are your healing potions in your arms band?"

Taiki probably has a couple in his as well, he carries them to give out if he sees anybody without and he can move to get one, it will just mean untangling himself from Tidus.