That's why there are other players on the roster. Kruger doesn't need to be physical, and being physical is overrated. What he does is what this team needs, a shutdown C outside of Toews, or else Toews won't be as good offensively. He has earned a cap hit north of 2mil already.
Danault isn't going to come in and replace Kruger, simple as that. He may eventually, but not right away. I may agree that 3mil may be high, but you better find someone who can do what he does in a hurry, and Danault won't be doing that right away.
Or maybe it's because Saad is better?