Look, I like Perk and everything, and wouldn't mind him being a lifetime Celtic role player for the right price. But, for once, let's put his place in our 4-big rotation in perspective:
Offensively, we know he's dead last of 4, right? Okay...
In this series, despite his ability as a physical LOW post defender, Gasol plays high-post more than low. IMO, KG and Sheed (gasp) have been at least as good defensively as Perk, and perhaps better. BBD's lack of length puts him a clear 4th of the 4.
So, if Perk does go down and we're down to a 3-big rotation, which is all that LA uses in the first place, and the odd guy out for us due to injury is our 4th best offensive player and 3rd best defender, and the next best defender (BBD) still has the ability to out-muscle, if not out-reach, LA's bigs, then there is no way that Perk being out should in any way decide the game or series.