TORONTO ― As the Celtics navigated this uneven stretch over the past month, they mostly struck an upbeat tone. They cited their record that remained the third best in the NBA. They pointed out they have rarely been at full strength. They reminded everyone they are, in fact, the defending champions, and they are aware what it will take to regain that form.

But after Wednesday night’s disheartening 110-97 loss to the 10-win Raptors, there was a new, ominous air of frustration and urgency that has rarely surfaced around this team over the past two seasons.

“I think we played with no spirit, with no personality,” Kristaps Porzingis said. “It’s just a weak performance from us, honestly.”

Porzingis said there were times the Celtics appeared to be just going through the motions as the Raptors streaked to the basket for layups with simple off-ball cuts. He said the Celtics played “some bad basketball.”

The only time Porzingis flashed a hint of a smile was to tell the group of reporters that even if he was panicking, he would not tell them. After that lighthearted admission, he insisted that he was not, in fact, panicking, and he trusted everyone would believe him.

“But we are in a bad moment right now, for sure,” Porzingis said. “We have to be realistic and look in the mirror. We’re not playing the best basketball. We’re not executing … There’s a lot of things we’re not doing well, and we have to be honest with ourselves, otherwise we’ll just keep going like this.”

Yes, the Celtics are 28-12 and in second place in the Eastern Conference, but that mark does not really tell the story of the team they are at the moment. They are just 7-7 in their last 14 games, and if CJ McCollum’s buzzer-beating layup for the Pelicans had caromed in Tuesday, Boston would be staring at a three-game losing streak that includes losses to two of the worst teams in the league.

Jayson Tatum said it’s clear the Celtics need to find a way to play with “more intensity, more life.”

“We’re going through some [expletive] right now,” Tatum said. “It’s tough. But we said it after the game: We’ve got to go through it together, as best as we can, stick together, trust in one another like we always have, and just show your true character.”

Late in the third quarter, Tatum dribbled along the perimeter before Toronto star Scottie Barnes pushed him back toward halfcourt and loudly clapped in Tatum’s face to make it clear he was determined to stop the Celtics’ All-Star.

These Raptors fans have become more focused on lottery odds than wins, and some even appeared frustrated by this night not helping on that front. But at this moment, everyone roared and enjoyed the burst of energy that used to be common in this building.

The scene appeared to agitate Tatum, who responded by using a screen to roar down the lane and attempt a monstrous one-handed dunk. Then the ball was rejected by the rim. Tatum claimed he was fouled, but the frustrating sequence summed up Boston’s night.

Tatum had just 16 points and Jaylen Brown added 10, with the All-Star duo combining to make just 9 of 31 shots. The Celtics shot 39.1 percent from the field.

“All of us are wearing [the missed shots] a little too much on our face,” Tatum said, “and we’ve got to get out of that.”

RJ Barrett led the Raptors with 22 points. Toronto scored 60 points in the paint and shot 50.6 percent from the field overall.

But there is a wide talent gap between these teams, and the Celtics have shown it does not take much for them to erase deficits. So when they started the fourth quarter trailing just 88-82, a run felt inevitable.

Instead, Boston crumbled. In the final period the Celtics shot 6 of 20 from the field, surrendered seven offensive rebounds, and scored just 15 points.

There were several stretches during the game in which the Celtics appeared to display a lack of effort, particularly when the Raptors either gobbled up second chances or sliced to empty space with a simple cut.

Celtics coach Joe Mazzulla disagreed with the suggestion effort had waned, however. He said it was simply a matter of attention to detail and pointed out this style of play is Toronto’s strength. Whatever the reason, it was not pretty.

Now the Celtics will begin a challenging stretch that includes six of seven games against teams with winning records. The lone exception is a road game against the Warriors (19-20), who still figure to be dangerous for obvious reasons.

“We know we will get past this,” Porzingis said. “We know it. I know it. But we have to start. We have to start playing better. We just can’t keep cruising and expect to just turn it up toward the end. So, it’s in our hands.”