Sadly I think most proper fixes to our d-core seem like they are more likely to be available at the deadline, just looking around the league at RHD that I think could be available now:
1) Trevor Van Riemsdyk- like us they need to cut cap and seems almost certain they'll cut either him or Ethan Bear, but I'm guessing he's more likely since he makes more and Bear was a more recent signing (though I also had no clue about his substance abuse issues and if that changed how the org felt about him). Regardless, I don't really see him as an upgrade on Ceci, kind of lateral or potentially worse.
2) Henri Jokiharju- I don't have enough views on the player to have a great grasp on him, but it appears the Byram trade made him a little more expendable, between Power, Dahlin, and Byram they are developing many young D at the same time, while Jokiharju is 25 I think it might still be a little too much at once, the org seems like it really wants to take a step forward and getting a little older to properly mentor their young d-core seems smart. While contenders generally don't look to this age range or experience level for D fixes, his analytics make me think he might take that next step and with our limited capspace we do have to be somewhat frugal in finding fixes.
3) Will Borgen- He got pushed down the pecking order with the Montour signing, a big mobile defensive defenseman, defends well, good stick, has a little bite to his game. Hasn't fully established himself as 2nd pairing quality so on paper it kind of seems lateral, but I think his higher level skating will prevent him from being victimized on the forecheck like Ceci and I find the speed at which he adapts to plays on the fly will elevate him a notch above, I think both Nurse and Ceci have deer in the headlights moments when unfortunate bounce or the unexpected occurs, but Borgen doesn't seem to miss a beat and actively compensates, which is something I think Nurse needs in a partner; maybe not as good of a puck mover as Nurse might need, but IMO this is a very reasonable gamble if we want to take an early shot at trying to patch a hole.