NEW YORK — Joe Mazzulla admitted before Wednesday’s season opener that the Celtics didn’t have an identity last season. The circumstances of the beginning of that training camp simply didn’t give them enough time. But with enough preparation going into this season, Mazzulla emphasized the importance of setting one.

“Humility. Mindset. Toughness. Passion. Togetherness. Just be nasty,” Mazzulla said. “So we’ll see if that happens.”

The first test came Wednesday. In control for most of their opener, the Celtics suddenly let go of the rope. They were unraveling. The Knicks and their rabid Madison Square Garden crowd smelled blood. But they never tasted it.

The expectation is that these Celtics, with their superior top-end talent, should breeze to at least the conference finals, if not win the whole thing. But Wednesday revealed they’re unsurprisingly not close to a finished product. On Wednesday, they relied on that newly formed identity to tough out an ugly but gritty 108-104 victory over the Knicks.

Jayson Tatum scored 34 points and Kristaps Porzingis poured in 30 points in his Celtics debut, powering them on both ends and leading them to the finish line of this heart-pounding win. The C’s trailed for the first time in the fourth quarter but proved resilient late with defense and toughness to scratch their way to a season-opening victory.

More to come…