The keyword in the report is "absorb" not, "trade for", they're looking for a team that can take on Calderon's deal preferably for draft assets, and not have to kick back money.
Neither Toronto or Memphis has interest in taking in more money, they need someone to take on Calderon's deal so that they're sending enough salary out to fit Rudy in under their cap and make the trade legal.
Bottom line is the Celtics can't get involved here, because they'd have to send out equal salary, and neither team has any interest in that salary.
For Boston to get involved, you'd need a 4th team with open space that wants some of (10.5million worth to be exact) boston's players, and has the cap space to take them.
I don't think there are any teams out there with cap space who are just absolutely dieing to get ahold of Jeff Green or Brandon bass in order to facilitate this.