It seems like Jakob Chychrun's name has been in trade rumors for a long time now. He has the skills and the talent to be an effective top four defenseman. However, the former first round pick has had a difficult time staying healthy. In the last six seasons, Chychrun has never played an entire season. This year he still has not skated in a game all season as he is recovering from off-season wrist injury.
The Leafs already have TJ brodie and Jake Muzzin on long-term injured reserve. They certainly can't afford to lose more defenders. Who knows if Jake Muzzin comes back to play as he is dealing with serious health issues. So the need for a top four defender is certainly there for Toronto. But it has to be the right fit and a healthy player.
You would think many teams would be cautious about acquiring Chychrun. Remember when the Philadelphia Flyers traded for Ryan Ellis? He's played a grand total of four games for them. I believe that your seeing all NHL teams be weary of who their trading for and what their health status is nowadays. Of course there are no guarantees how trades will work themselves out but teams don't want to give up future assets for a player who can't stay healthy and provide little value. Unless Arizona makes Toronto an offer it can't refuse, it's unlikely Toronto gives up picks and prospects for Chychrun.