BOSTON -- Joel Embiid heard the criticism directed at him by Charles Barkley and Shaquille O'Neal.

And, according to Embiid, they are right.

"Maybe they're right. Maybe. I do think they're right. I think I need to be more aggressive, and just look to impose myself and look to dominate," he said.

"I think the whole season I haven't done that, and you can see the way it has affected my efficiency and my stats, so I guess I need to go back to having fun and just dominating. But I get what they are saying and I think they are right, man. I have to make a change."

While Embiid had 22 points, 10 rebounds and six assists going up against fellow All-NBA center Nikola Jokic Tuesday night, that wasn't good enough in the eyes of Barkley and O'Neal, as they both criticized Embiid for his effort and failing to dominate games in the way they think he should.

"He's the toughest player in the league to match up with," Barkley said on TNT after it showed the game Tuesday. "But we don't talk about him the way we talk about Luka [Doncic], Giannis [Antetokounmpo], Anthony Davis, James [Harden]. We don't ever say that about him.

"It's frustrating for me, because I picked the Sixers to get to the Finals."

As for O'Neal, he said, "We're telling you, 'You can be great. You ain't playing hard enough.' Twenty-two [points] ain't enough to get you to the next level.

"Do you want to be great or do you want to be good? If you want to be good, keep doing 22 points. You want to be great, give me 28, give me 30. You want to be great, watch Giannis -- he wants to be great."

Embiid's averages this season are still eye-popping -- 22 points, 12.4 rebounds and 3.1 assists entering Thursday night's nationally televised game against the Celtics -- but his shooting percentage (45.8) is lower than it was last season, and he's clearly been impacted by the way the Sixers chose to remake their team in the offseason.

By moving on from JJ Redick -- who had brilliant chemistry with Embiid during their two seasons together in Philadelphia -- and signing Al Horford, an already spacing-challenged offense became even more so. That, coupled with Embiid playing fewer minutes than he did last season in an effort to stay healthy for the playoffs, has left him trying to find a rhythm in a new environment.

"I mean, I said earlier that I want to get to the playoffs healthy," Embiid said. "The last two years I was not healthy. Two years ago it was my face, and then last year it was my knee and I was sick. This year, I kind of told myself I want to get there healthy.

"We got a new group. I'm still trying to get used to it. It's different. It's completely different. The way I'm being guarded this year, every time I touch the ball, heavy double-, triple-teams.

"[I'm] just trying to navigate through it. Just be a basketball player, make the right plays, if I get double-teamed my teammates know I'm going to pass it, so it's about balancing between trying to make something happen for your team and making the right play."

On a team with shooters around him, perhaps Embiid would have the kind of spacing that would allow him to relentlessly attack single coverage inside. But that isn't what his life in Philadelphia is like for Embiid. Instead, Philadelphia is the biggest team in the league across the board, leaning into the strengths of its best player and trying to beat its opponents into submission at both ends of the court.

That begins with Embiid, one of the league's best defensive players and its most dominant force in the post. But, he said, he knows that if he has an off game, people will look at him -- like Barkley and O'Neal did -- and expect more.

"That's the high standard that I guess that I set," he said. "It just feels like if I don't score 35 points or, I don't know, 40 points, it feels like it's a down game, even when I have 30. It's just the way it is. I signed up for it.

"I want to be great. I put the work in to be at this level and to be better, and I still feel like I have a lot of potential, and people feel the same way so it's only right for people to expect me to, like Shaq and Charles said, to drop 35 a night.

"I'm not a selfish player, I take whatever the defense gives me, if they're going to double-team me all night and I only take two shots, I'll do that, too. I've got to play within the concept of the game and follow whatever the team wants me to do. I've been following it, and if it takes me taking five shots a game I guess I've got to do it."

Gordon Hayward took a hit to the face Wednesday night in a loss to the Indiana Pacers, but the Boston Celtics said he is probable to play against the Sixers. Marcus Smart (eye infection) and Robert Williams (hip) remain out.

For Philadelphia, Horford -- who is back in Boston for the first time since he left the Celtics to sign with the Sixers as a free agent this summer -- is questionable to play with a sore left knee and left hamstring tightness.