That's not how the d-league works. To free up his roster spot we'd have to waive him, another team would be free to sign him then. Another team would take him on as a project certainly. Especially since it wouldn't be for guaranteed money.
I'm not sure what you are saying here.
If we wanted him off the roster to free his spot - sure, we'd have to waive him.
But we don't need to do that to send him to the D-league. The new CBA allows teams to send guys in their first 2 years back & forth to the D-League unlimited times.
And there is no need to waive him for his roster spot anyway as we currently only have 13 players on the roster - we have 2 open roster spots.
OP said the C's get another player for his roster spot before an edit to clarify what he meant.
Oh - okay. 'Wuz confuzed for a moment! (You normally make a lot more sense than that seemed!)