Trading Larsson would be a mistake at this time. Coming off a bad season last year, substantial injury this year, and he wont look great for a while once he gets back, his value will be low anyway you slice it. Not to mention his value as a depth defender to the team. He's no longer top pair calibre, he's in Marc Staal territory, a stable and steady bottom four guy.
That being said, there is that logjam building. Persson and Bear are continuing to improve, if they both have successful seasons, with Bouchard on the doorstep, and Benning and Larsson as well, it becomes something of a numbers game. Depth is great, but you need to find room for all of them.