This isn't a knock on the man or his production. He is 31 years old and he hasn't yet seen his production begin to decline in any significant way. He was for the most part on par with career averages last season, recording 43 points in 64 games. He is and will continue to be a feisty, well rounded, puck moving defenseman. A salary cap hit of 6.5 million for a blue-liner with his level of consistency isn't a bad contract either, but as previously mentioned, the Blues are in a tight spot.
Now that the Tkachuk sweepstakes have been awarded I certainly don't believe Krug will be moved before the season. And predicting trade deadline moves for a season that hasn't yet begun is a fools errand. But it would not be a major shock to me if he is shopped to other teams at the deadline, assuming the Blues aren't battered by injuries and Perunovich is comfortable with a larger role. Because while they do have a strong roster, the Blues will absolutely have to do something to create significant cap flexibility, and the sooner the better.