Porzingis said there were times when the Celtics looked like they were just going through the motions while the Raptors used simple off-ball cuts to rush to the basket for layups. He said the Celtics played “bad basketball.”

The only time Porzingis flashed a hint of a smile was to tell the group of reporters that even if he panicked, he wouldn’t tell them. After this light-hearted admission, he insisted that he was not, in fact, panicking and trusted that everyone would believe him.

“But we are certainly in a bad phase right now,” Porzingis said. “We have to be realistic and look in the mirror. We don’t play the best basketball. We don’t implement it… There are a lot of things we don’t do well and we have to be honest with ourselves or we’ll just keep doing it.”

Yes, the Celtics are 28-12 and in second place in the Eastern Conference, but that record doesn’t really tell the story of the team they are right now. They are just 7-7 in their last 14 games, and if CJ McCollum’s stunning layup for the Pelicans on Tuesday had been successful, Boston would be looking 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 and more life.”

“We’re going through some (expletives) right now,” Tatum said. “It’s difficult. But we said it after the game: We have to get through it together, as best we can, stick together, trust each other as always and just show our true character.”

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

These Raptors fans are more focused on lottery odds than winnings, and some even seemed frustrated that tonight wasn’t helpful in that regard. But at that moment, everyone was roaring, enjoying the burst of energy that used to be common in this building.

The scene seemed to energize Tatum, who responded by racing down the alley using a screen and attempting a monstrous one-handed dunk. Then the ball bounced off the rim. Tatum claimed he was fouled, but the frustrating sequence summed up Boston’s evening.

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.

“We all take (the misses) a little too much in our faces,” Tatum said, “and we need to get out of there.”

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

However, there is a huge talent gap between these teams, and the Celtics have shown that it doesn’t take much to make up for deficiencies. So when they started the fourth quarter trailing by just 88-82, a run seemed inevitable.

Instead, Boston collapsed. In the final period, the Celtics shot 6 of 20 from the field, gave up seven offensive rebounds and only scored 15 points.

There were several periods during the game where the Celtics appeared to show a lack of effort, particularly when the Raptors either capitalized on second chances or hit a simple cut into space.

Celtics coach Joe Mazzulla disputed the notion, however, saying the effort had waned. He said it was simply a matter of attention to detail and pointed out that this style of play is Toronto’s strength. Whatever the reason, it wasn’t pretty.

Now the Celtics begin a challenging stretch that includes six of seven games against teams with winning records. The only exception is an away game against the Warriors (19-20), who are still considered dangerous for obvious reasons.

“We know we will overcome this,” Porzingis said. “We know. I know it. But we have to start. We have to start playing better. We just can’t keep going and expect to just turn it up a notch towards the end. So it’s in our hands.”

Adam Himmelsbach can be reached at [email protected]. Follow him @adamhimmelsbach.