I heard John Fox say Champ is 'hopeful' for game 1 of the regular season. Look, they X-rayed it, MRI'd it, the only thing they didn't do was hold it up the to night sky and chant to the gods, and there was no structural damage.
It's a strain. If anyone here has ever strained their arch, you know how painful that can be, but it eases up like any muscle strain, and I bet Champ is back full strength very soon. Maybe not game 1, but soon.