LAKE BUENA VISTA, Fla. -- After he likely coached his final game with the Philadelphia 76ers, coach Brett Brown said he has never gotten a chance to show his full potential as a coach over his seven years with the franchise because of the numerous injuries that have cropped up during his tenure.

"No," Brown said flatly when asked that question Sunday after the Sixers lost to the Boston Celtics 110-106 in the final game of a four-game sweep in the first round of the NBA playoffs.

When Brown was asked if he would like to elaborate on that point, he responded, "No. Thank you for asking the question."

During Brown's seven years in charge, the team has dealt with many injuries, including to franchise cornerstones Ben Simmons and Joel Embiid, former No. 1 pick Markelle Fultz and others. The latest injury to befall the Sixers was the loss of Simmons for the remainder of the season after he required surgery to remove a loose body from his left knee earlier this month.

His absence was acutely felt against the Celtics, who took full advantage of Philadelphia being without one of the league's best and most versatile defenders on the perimeter -- led by emerging star wing players Jayson Tatum and Jaylen Brown.

"Missing Ben will resonate for a long time, especially given what he did to prepare himself to play in the [bubble]," Brown said. "The difficulty of guarding the Celtics' wings [that] you live every time you play them is they've got so much firepower, and you really need to have a stable of able, senior, veteran-type mentality defensive players on a bunch of really good scorers. And I will think of [not having Simmons].

"Obviously, the way our season ended is disappointing. You can't, obviously, phrase it any other way. But really trying to guard those wings was difficult."

Philadelphia had its full projected starting five -- Simmons, Embiid, Tobias Harris, Al Horford and Josh Richardson -- for only about 20 games this season, something Brown lamented after Sunday's loss.

Still, the loss of Simmons, or even the myriad injuries the Sixers dealt with all season, doesn't explain the complete lack of cohesion the team showed throughout it, both before the season shut down because of the ongoing coronavirus pandemic and after the league returned to play inside the NBA's bubble at the Walt Disney World Resort.

Richardson took aim at what he thought one of the problems was after the game, blaming Brown for a lack of accountability across the roster.

"He a good guy," said Richardson, who was traded from Miami to Philadelphia as part of a sign-and-trade deal for All-Star forward Jimmy Butler last summer. "He's a good man. He means well. I just think, going forward, he's gotta have some more accountability.

"I don't think there was much accountability this season, and I think that was part of our problem."

Last season, Embiid came out swinging in defense of Brown after the season was over, calling rumors about his potential demise "bulls---."

But when Embiid was asked, on multiple occasions, to say Brown should remain the team's coach after Sunday's loss, he did everything but do so.

"I don't know," Embiid said. "I'm not the GM. I don't make the decisions. All I know is that we've got a great organization, a bunch of great people outside of basketball.

"I never judge people based on basketball. I judge them based on how great of a people and how bad [of a] people they are. And I think in the organization, we've got amazing people, from the management, owners, management, staff, coaching staff, training staff. We've got a bunch of great people."

When Embiid was asked again about Brown, he said he's a great man -- but, again, did not say he should return.

"Great guy," he said. "He's an even better person than a coach. He cares about his players. He cares about people that work with him. It's beyond basketball.

"No matter what happens ... like I said, I don't make the decisions. I don't know what's gonna happen. I trust management and all that stuff. Like I said, he's gonna be a great friend no matter what."

For his part, Brown admitted he didn't do a good enough job this season, specifically with trying to find the right way to fit Horford and Embiid -- longtime rivals in the post who became teammates after the Sixers signed Horford away from the Celtics last summer -- together on the court to allow them to have success.

"I mean, it was difficult," Brown said of the challenge of fitting Embiid and Horford together. "But that is my job. That is the job of an NBA coach. You have to take the team that you have and maximize it and get the most out of it, and I did not do that.

"We came in and we talked about 'smash mouth' and 'bully ball.' We're built for the playoffs. We're big. Really all those kinds of phrases equaled, 'Man, we have a huge team.' We have a big team. And the thing that I found the most challenging as the season played out, space became an enormous issue. And effectively you had a mismatch every possession down the court. And the fact is, that's Joel's world. That's Joel's domain. And trying to help the team, trying to coach the team, conquer that problem I felt was a challenge. From a spatial issue, from a team sort of design, that was an area we needed to get done, and I don't believe I did that great of a job coaching that."

When Brown was then asked if the two can work together, he said he thought they could -- but then, again, said he could've done more to help them along.

"I think that they can," Brown said. "I think that they can. As I admitted, I didn't do a great job of coaching that side of it to project out and say can that happen. I believe that it can. It needs substitution savvy. It needs a bunch of things to get it as perfect as you wished it could've."

One player who did defend Brown after the game was Harris, who said that it was on him, as well as the rest of the players, to take the blame for things not going the way the Sixers had hoped this season.

"With Ben going down, I thought Coach did a good job trying to rally us up, get us going," Harris said. "Keep our spirits up game through game, we go down one game, go down two, so just keeping the mood up.

"Before anything I take ownership of myself and trying to be a leader on this team and not being able to be successful in the playoffs. Before we go that way, ownership got to come from the individual at the end of the day, so I'm not going one way or another. I got to look myself in the mirror and be better for my team and be able to lead my team in a better way."