If I recall we were within $3-$5 million of hitting the original competitive balance threshold with our March roster. So they had a couple million dollars of flexibility to stay under. The expanded roster took a million or two of that flexibility away. It is 12 person-weeks of expanded roster spots, but more like 32 weeks when pro-rated against a full season.
I think the Phillies want those 32 extra weeks at a minimum salary rather than one that might make $1.5-$2.0 million. I am not sure what the actual contract with Harrison was for, but one can be certain it had reachable incentives that could push it into more expensive areas and I believe incentives all get pro-rated too.