Honestly I don't think there's a doubt in the world that they add a d. Knowing dubas, he's aiming high. But if that fails I can 100% see Hainsey coming back. 100%.
As for Zaitsev, he will likely be a hotter commodity as the UFA d get plucked. There will be a trade to make there. But if he's gone I can see them getting 2 d. By all accounts they really really do not want to rush their young d. I don't think it's rushing but they do. Bobo said it, and then dubas said it. I trust them both. I can see one in the lineup if he has a good camp simply because Dermott is out, but not both.
Rielly-hainsey
Muzzin-zaitsev/new d (heed/tanev/etc)
Dermott-finnish guy/Rosen/liljegren
Think they may go into the season looking like that to be honest.