This was from Andy Larsen's triple team column after the win, for some insight as to why Walker isnt getting as many minutes as some here think:
So what’s keeping Kessler from permanent starter status? I think he only needs to evolve his game just a little bit. Olynyk is just better offensively, even though I think the gulf is wider between Kessler’s defense and Olynyk’s defense, and the Jazz are winning games just on the back of their offense, so it makes some sense to stay with the status quo.
I asked both Walker and Hardy what was one thing Kessler could do to make that jump into being a consistent starter. Hardy said that the biggest thing is that Kessler is a poor screener right now, drawing all sorts of offensive fouls while not doing a whole lot to free up his man. He’s working on it every day in practice, though.
Kessler, meanwhile, said that he wanted to become a more switchable player defensively. I agree with that, but think that matters most in the playoffs — you can win a lot of regular season games by just protecting the rim like Kessler does.