I will be upset if they can only sign Pietrus for the BAE, and do so. That's a waste of resources. They'd be better off signing him for his non-Bird max, which is only $300k less than the BAE, and either creating a little room with Jeff Green's contract to add someone with the BAE, or better (we'd be about $100-200k short of space assuming it's true that JG is scheduled to make $9 mil flat this season), or, better yet, saving the BAE for next off-season, and keeping the final spot open for someone at the minimum, and with $1 mil open in cap room to add someone mid-season in case of injury/ineffectiveness on the roster.
I hope Pietrus comes back, but the non-Bird should be his maximum.