Here is a quick summary of each team's remaining schedule.
SAC: Tough overall. The one easy game is LAL at home. Next easiest is MIN at home. Other than that, they play 8 game against playoff teams, 5 of which are on the road.
LAL: Also tough. Two games against bad teams (SAC, UTA) but both are on the road. The other 8 games are against playoff teams, though only 2 are on the road.
UTA: Two winnable games (NYK and LAL at home). Seven other games against tough teams, 4 of which are on the road.
BOS: Clearly the easiest. Three games against terrible teams (PHI, PHI, CLE). Two other winnable home games (CHA, WAS), and a possibility of stealing one on the road (WAS, ATL, DET).
I hate to say it but this does not look good for the Celtics. If we go 4-6 we will almost certainly end up with the 7th lottery slot.
I think if we go 2-8 we will end up 5th.
If we go 3-7 I think it's a crapshoot.