He’s one of the best forecheckers in the league, played to a roughly 30-goal pace over each of the past two seasons, is an excellent penalty killer, and he’s even capable of carrying his own line. For the Leafs, a big plus was that he could slot alongside their elite players seamlessly, do the dirty work (so to speak), and contribute offensively.
With little in the way of cap space, the Leafs were never going to replace him, nor did anyone expect them to.
They kept the rest of the core together and backfilled the roster reasonably well all things considered – players like Michael Bunting, Ondrej Kase, and David Kampf have played as well as could be expected so far, although Nick Ritchie has struggled out of the gate.