I wonder if Ottawa is also sending one of their LTIR guys as well.
I doubt the Leafs want to take on a big LTIR cap hit. I also don't think it benefits Ottawa to move Gaborik or MacArthur. Both are apparently insured which makes them great assets for the Senators. The Senators can get almost 10 million worth of cap space covered while paying much less than 2 million in real dollars.
Harpur will 100 percent be in the trade. Makes too much sense since it costs the Leafs nothing cap wise. Sens might have to take an AHL contract though.
Condon is the next most likely. 1.4M cap hit against a 3M salary. Toronto had interest in Condon when he was a UFA, so there's a connection there. The Leafs obviously would only be taking him to facilitate dumping Zaitsev, not because they want Condon, but maybe because they liked the player previously they might think they can make something good out of him as a cap dump and rejuvenate his career as a possible candidate for their backup job.
Zack Smith would be a dark horse. 3.25M cap hit. Placed on waivers last year by the Senators. There was interest from teams, but they wanted Ottawa to hold back cash. Fits a need of Toronto if their player evaluation is off enough to think he's still a gritty 3C who can score. Toronto would move Kadri for assets and replace him with the slightly cheaper Zack Smith.