the thing the Cavs can keep "play" on is that
Per Celtics analysis, what they believe is that IT4 may not be ready at the beginning of the season...but will be ready soon after (and even CBS/Danny made it sound this way)
The Cavs can say on the other hand.... there is a decent chance, he will miss the 1st half of the season. We don't want to take any chances and bring him back too quickly. There is also a small chance if he comesback, reinjures or surgery is the best course of action.....well we are out of a player. A player we were going to depend on , to do some heavy lifting
Danny can disagree with this assessment....at the end of the day nobody knows for sure.
Just add the multiple 2nds and get this done. If the Cavs balk at this addition, I would then take it up with the league and let them intervene.