Non professional opinion: at worst its a high ankle sprain. Looked just like a sprain you see in every basketball game. Considering his position I doubt it would keep him out more than a couple weeks, maybe a month.
I prefer Perin anyway, but if it’s something worse, we can’t have Pinsoglio as our #2. If it’s fractured they’ll know immediately so they’ll have time to get someone else on loan or something.