This seems to happen relatively frequently on Draftkings. A more or less "manual" work-around for a specific day is to find a defenseman with the identical salary of Dustin Byfuglien for that night that you KNOW YOU DON'T WANT and assign that defenseman the points points projected by FC for Byfuglien. Then, when you run your projections if the name of that "unwanted" defenseman appears in your lineup you just need to remember to use Dustin Byfuglien instead of the unwanted defenseman when you enter the lineup in Draftkings.

This should work as it's my understanding FC only uses Position, Salary, and Projected Score in computing lineups (and not Consistency, or Projected Score Above Average, etc).

This is what I've been doing.

So FC wouldn't need to worry about these Draftkings mistakes, a permanent solution would be to allow users to override the player's position in the same way we can override projected fantasy points by entering our own points projections, i.e. replace RW with D. Since this seems to be just a Draftkings NHL thing, maybe FC could only allow it for NHL games on Draftkings and not for other sports or other sites like FanDuel.

Anyway, hope the first solution helps, at least in the short-term.