Joe Mazzulla made a tremendous impact on the Boston Celtics during their pursuit of Banner 18 last season.

Whether it’s the emphasis on 3-point shooting, the team’s stellar defense, or its unselfish style of play — Mazzulla has made his imprint on this group in so many ways.

But despite the enormous success Mazzulla has enjoyed in his two seasons as Celtics head coach, he still doesn’t get the level of respect and recognition he deserves, at least nationally. When you look at rankings of the NBA’s best coaches, he’s often left outside the top five (or even top 10). He finished fourth in Coach of the Year voting last season despite the Celtics finishing with 64 wins — at least seven more than every other team.

Why is Mazzulla still overlooked?

“Brad (Stevens) luckily didn’t overlook him when he promoted him. It was completely Brad’s recommendation and decision to promote Joe to coach, which was brilliant,” Celtics lead owner Wyc Grousbeck told WEEI’s The Greg Hill Show on Tuesday.

“I would say the first year, honestly, we had ups and downs, and we grew into it. He was thrown into the fire like one day before training camp, I think, and was interim, and then made him permanent because he earned that. We had the best record in the league at the time, but we didn’t take it all the way. There might have been some growing pains or ups and downs in the first year.

“He really grew into it last year, and he seems to be on a whole other level this year. Just the quotes yesterday and everything else, he’s just getting started. Let’s see what Joe has for us. I personally think he’s one of the very best coaches — or the best — that I’ve ever met.”

One skill that the best coaches have is an ability to manage egos and keep superstars happy. The team chemistry on the Celtics is fantastic, and Mazzulla has a lot to do with that. He connects with the players on a personal level.

“Joe just connects with you. He is about you. He’s about I love you, I want you to be your best, and I’ll do anything I can to achieve that,” Grousbeck said.

“He’s got this magnetism to him, and it’s completely authentic. That’s probably a different style than some of the other coaches out there. It’s probably not the Red Auerbach style of coaching or Vince Lombardi – It’s Joe. It’s unique, and it really has connected with our guys. They would do anything for Joe. That’s what you want in a player-coach relationship.”

Mazzulla did a great job motivating the Celtics throughout the 2023-24 championship season, but his challenge ahead of the 2024-25 campaign might be even greater. No team has repeated as champs since the 2017-18 Golden State Warriors, and the Celtics as a franchise haven’t won back-to-back titles since Bill Russell was player/coach in 1969.

But based on both his and the players’ comments about the task in front of them, the entire team seems well-prepared entering its title defense.

It all starts Tuesday night when the Celtics host the New York Knicks at TD Garden.