In an appearance Monday on ESPN's "The Jump", Smart admitted the team was dysfunctional but stated that every Celtics player had a role in the club's disappointing second-round postseason exit.
"Let's call a spade a spade, right? It's true. We were dysfunctional," Smart said. "It takes a lot for guys, and especially athletes, to own up to that and say, 'Yeah, things didn't go quite as how we wanted.' But we gotta look ourselves in the mirror (and ask) 'What did I do? What could I have done to help?'
"We all took part in it, we all could have done something better to help that team."
Kyrie Irving - now a Brooklyn Net - has received the brunt of the blame for the Celtics' state of disarray in 2018-19. However, after staunchly denying that Irving's leadership was a reason for the team's disappointing finish in May, Smart explained why his former teammate was far from a bad egg in Boston.
"For me, personally - I can't speak for the other guys - but for me personally, Kyrie's a great teammate," Smart said. "I've had sit-downs with Kyrie where things for me probably wasn't going so well, where he was pulling me to the side and it wasn't even about basketball.
"Everybody knows what I went through with my mom, losing her and everything. Kyrie - one of the first guys to text me, call me. When I got back to Boston, (he) pulled me to the side, we sat down and we talked. As far as basketball, just helping me slow the game down and really recognize and understand the game even more."
Smart continued: "So as a teammate, I loved him for it. That leadership that he's been drawing and want people to show that he has - he had it, it was going. ... He's just misunderstood."