Responding to several previous comments, the Celtics are playing like they believe making the playoffs is a given. It does not appear to me that their heart is fully into every regular season game, every quarter. But I am not sure this is a problem. I would certainly prefer to see them play well every game, every quarter, but that is probably not realistic.
To me, there is a qualitative element to this that you have to judge by watching. Are they losing or playing bad because they are missing shots and/or just not playing with energy, or is the other team flat out beating them. And if the other team is flat out beating them, is it because they are just hitting shots at an unsustainable pace or is it more than that.
Of the recent losses, I would say that the LAC game was a case of them just being better on that night. We didn't have Porzingis which matters but LAC outplayed us, not just out shot us. In the DEN game, I felt that was a case of them just plain out shooting us. The DEN game concerns me less than the LAC game.