There are only two teams that are still in playoff race and I am pretty sure you already know, Raptors is one of them while the Bulls is the other one.
Against Raptors, Cavaliers played all their players without significant less minutes then the average minutes played for the entire season. Obviously they beat Raptors and put CB4 out for at least a week, seriously affecting Raptors chances to get into the 8th spot. Tonight, Cavaliers will play against Bulls ... do you think is ethical for them to rest their best players and eventually let Bulls win?
Also, Cavaliers have the luxury to decide who to play in first round of playoffs. If they would liked to play against Raptors, they could have rest the best players against the Raptors, which they didn't. This make me think that Cavaliers may prefer Bulls for first round.
Personally, I think that the direct game between Bulls and Raptors will decide the fate, but at this time any W/L matters in the end. Raptors still have the tie break over Bulls