"It starts on defense. I thought I was s---ty. I thought we were all bad tonight," Embiid said after the Sixers allowed Boston to hit 17 3s in a 16-point defeat. "That's not who we are, definitely. I think when everybody's on, we're the best defensive team in the game. There's a lot of stuff that we game-planned that we didn't execute."
Philadelphia allowed the undermanned Celtics to shoot 49 percent from beyond the arc in a lopsided loss to open their second-round series.
"I thought this was one of our poorer defensive games," coach Brett Brown said after Philadelphia lost for just the second time in the past 22 games.
"I think, to look at this game, defensively, offensively, this isn't who we are," Brown added. "This is a very poor game from us."
The Sixers couldn't get anything going on offense, missing 21 of 26 3-point attempts and shooting 42 percent overall.
"Give [the Celtics] credit. I never thought we were in the game," Brown said. "We're gonna have to fix some things. I'm gonna have to back up my words with our group."
Philadelphia had six days off after eliminating the Heat in five games in the first round. Some players cited that long layoff as one of the factors behind Monday's blowout defeat.
"I think they came ready to play and we were very rusty, and we just got smacked multiple times and we didn't react. I think that's what it was," Ben Simmons said after the Sixers missed 15 of 20 shots to open the game.
Simmons and Brown both felt the Sixers failed to move the ball enough in Game 1; ball and player movement had been a hallmark of Philadelphia's offense during its recent run of success.
The Sixers entered play Monday ranked second among playoff teams in assists per game (26.6) and finished with 22 in Game 1.
"That's one of the things we need to look at and reassess," said Simmons, who finished with 18 points, 6 assists, 7 rebounds and 7 turnovers.
One thing that didn't seem to bother some of the Sixers on Monday night? The crowd in Boston. Embiid, who had 31 points and 13 rebounds, said the crowd noise at TD Garden was "OK."
"I think our fans are louder than that," Embiid said. "It didn't bother me. They were great. They supported the team tonight. It was good. I love that type of atmosphere because it kind of elevates my game. ... I love when people talk trash, so keep bringing it on and we're going to see how it goes."