Defense
The backend is a little shaky. There's much to like with Calen Addison, Ty Emberson, Jan Rutta, Jake Walman, Henry Thrun, and Mario Ferraro. Ferraro, Walman, and Emberson are dynamic defensemen who will all play well based on what they have done in the past. The issue lies in finding the right supporting cast for those three. Addison will likely quarterback the powerplay, but that doesn't mean he should partner with one of the top four.
Jan Rutta is a great defenseman who has achieved a lot in his career, but he wasn't good last year and is starting to show signs of decline after he arrived from the Pittsburgh Penguins. If he can go back to being the defenseman he was as a member of the Tampa Bay Lightning, he could be serviceable, but he's also on the older side, and players decline at his age. He could be a third-pairing guy, but the risk of putting him in the top four is considerable.
So, that leaves Henry Thrun, who had a fantastic season last year. Can he replicate it? Even if he can, you can make the same argument about Emberson, who I said will probably be fine in a top-four role. The defense needs reinforcements, or it needs help from the forward core. Both will work, but there's a slight worry regarding the setup with this back end. Perhaps it will be good enough, but that is far from certain.
There is help on the way. Shakir Mukhamadullin looked good in the games he played at the end of the season. Sam Dickinson has signed his entry-level contract, and we will see what happens with him, but the reinforcements will not arrive quickly enough for the Sharks to have an impact this season. The future is bright in the Bay Area, but there is no immediate fix for the current issues on the blue line.