Zadorov would be an intriguing option for the Leafs. The team was clearly not good enough on the blueline this season and they could use some size and reliability on the back end. Interestingly, the rangy defenseman has reportedly rejected a big contract from the Vancouver Canucks. As such, he may very well be available on July first, but he will come at a cost.
Another option to upgrade on the blueline would be Stars defenseman Chris Tanev. Like Zadorov, he was traded by the Flames ahead of the trade deadline this season. He's been a vital part of the Stars on their playoff run this season, playing big minutes in a shutdown role.
Like Zadorov, Tanev will not come cheaply. However, it is clear that the Leafs need to upgrade that blueline. It should be very interesting to see if Treliving brings in any of his former players to the Leafs this summer.