Mediocre and average are terms that accurately describe the Celtics as they approach their Christmas Day matchup against the Nets, the start of a critical four-game road trip. And they can’t admit otherwise.

The 13-13 Celtics already have had too many wouldas, shouldas, and couldas this season. Five of their losses have come to Milwaukee and Philadelphia, they lost by 20 points at Detroit, they have dropped two decisions to Brooklyn, and they have been beaten handily by Houston and Chicago.