ATLANTA – It took Brad Stevens far longer than normal to emerge from his coaches’ office and address the media Tuesday night in Atlanta.

The reason for his delay was rooted far deeper than only Tuesday’s 121-97 drubbing at the hands of the Hawks.

“We had this coming,“ he said, still simmering a good 20 minutes after the conclusion of the game. “We haven’t played well in a few days now, even when we beat Brooklyn at home and we had a good quarter.

“We had this coming.”

Stevens, for the first time during his tenure with the Celtics, admitted that he needed extra time to cool down before speaking with the media. Isaiah Thomas said that he had never seen his coach as upset as he was inside the postgame locker room.

“I would’ve been in this (Celtics travel) outfit six minutes sooner if there weren’t fines involved,” Stevens said, with nothing but honesty in his voice. “I would’ve asked to be.”

The coach has good reason to be upset.

Boston has now lost two consecutive games in convincing fashion. It fell to the Nets Sunday evening in Brooklyn, 111-101, in a game that was not nearly as close as the score would indicate. The Hawks then picked the C’s apart throughout the duration of Tuesday night’s game, to the tune of 56.3 percent shooting.

Clearly, there are issues that are surfacing for Boston, and they start at the defensive end of the floor. Stevens went so far as to call his team’s defense “a sieve” and to say that it would be nice “if we guard somebody once.”

From an outsider’s perspective, it seemed as if the Celtics just didn’t bring it from the opening tip during its last few games. A few of the players, however, believe that Boston’s struggles are originating far before the team takes the court for game action.

“We had a bad walkthrough after the Brooklyn win going into Brooklyn and it rolled over into that game,” said Jae Crowder, who finished with only six points and three rebounds Tuesday night. “We didn’t have a good walkthrough today and it rolled over into this game.”

When pressed for details as to why those walkthroughs were so troubling, Crowder responded, “Guys not having the energy. Guys not being 100 percent locked in. It’s like faking it and get it over with.”

Those are some of the strongest words to come out of Boston’s locker room in recent memory. And they didn’t end there.

Avery Bradley, who is the longest-tenured Celtic and the closest thing this team has to an unofficial captain, also called the Celtics out in a public forum. He, too, believes that his team has lacked effort during its most recent stretch of play.

“In order for us to be successful, everybody has to play hard,” said Bradley. “It can’t just be four guys. It can’t just be one guy. It has to be all of us.”

These are calls for accountability from two of Boston’s leaders. Crowder and Bradley are not-so-quietly demanding that each player on this team give it their all for the benefit of the team, be it with studying film, with participating in a morning shootaround, or with playing in a game.

Failing to do so, as we’ve learned all too quickly, will lead to underwhelming results.

“If we don’t play well, we’ll lose. It doesn’t matter who we play,” Stevens said bluntly. “If we play even less than that, we’ll get blown out, and that’s why we had this coming.”

Fortunately for Boston, as Crowder, Bradley and Thomas all noted, it has a chance to redeem itself, and quickly.

There is no time to dwell; there is only time to improve. The Celtics host the Philadelphia 76ers at 7:30 p.m. Wednesday night.

How, exactly, can the Celtics bounce back from their trio of lackluster performances? Stevens believes it’s all about getting back to the identity that made the C’s so successful over the past nine-plus months: playing as one.

“I think we have to reconnect,” he said. “We’re not playing basketball as a team on either end of the floor. We’ve had good quarters that have masked our deficiencies. We need to get back to being a team. We need to get back in one direction.

“We’ve got to be a team.”

Stevens said that it is his responsibility to make that happen. His players, however, know full well that it is their job to reconnect.

“I think it’s up to the players,” Bradley stated. “Brad can say a lot of things, but at the end of the day it’s up to us to go out there on the floor and play the right way.”

The Celtics have gained a reputation for playing the right way over the past couple of seasons. That reputation has been tarnished over their past three games.

It has led to flares of emotion – anger, even – from the team’s strongest voices. Anger, because Boston knows that it is better than what it has shown over its past three games.

Come Wednesday night, it will be time for the Celtics to prove that such is true by reconnecting as one.