Sep 29, 2025; Boston, MA, USA; Boston Celtics head coach Joe Mazzulla talks with reporters during media day at the Auerbach Center. Mandatory Credit: David Butler II-Imagn Images David Butler II-Imagn Images

Joe Mazzulla Disagrees With Viral Claim About Celtics Training Camp

Originally posted on Boston Celtics on SI
By Patrick Warren | Last updated Oct 6, 2025 11:00 AM ET

It's no secret that Boston Celtics head coach Joe Mazzulla is known for his intensity. It's a large part of what. makes him the effective, championship-winning coach Celtics fans have grown to love.

However, Mazzulla challenged an assistant coach's claim regarding the intensity of this year's training camp.

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Assistant coach Sam Cassell told 98.5 the Sports Hub last week that this year's camp stood out among the many others he'd taken part in over his career as both a player and coach.

"We're going to be the hardest playing team in basketball and that’s how camp is going right now," Cassell said. "I’ve been in this business 34 years, my 34th training camp and this is the hardest training camp (I’ve seen) right now. It’s only one day but it’s a lot and our players are embracing it.”

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Mazzulla didn't buy his assistant coach's claims.

“I don’t really believe that,” Mazzulla told reporters. “Everything in this world today is about recency bias. Every time it’s like, 'oh this is the best ever.' We don’t remember the way we felt last year or two years ago or three years ago. So that’s just a classic recency bias of whatever you’re going through right now is the biggest, the best, the most important, hardest, easiest. None of that really matters. It’s all the same. It all depends on where you’re at in the moment.”

In his initial remarks, Cassell spoke of the Celtics' desire to be the hardest-playing team in the NBA — which could perhaps explain the intensity of training camp so far.

"This training camp we have right now, Joe wants to push the envelope," Cassell said. "He wants to force the issue. Not break them but take them to a point where this is hard. That's how we're going to have to play this year. We're going to play this year balls out and turn our hat backwards and get after it. That's Joe Mazzulla."

The Celtics will open the preseason with a matchup against the Memphis Grizzlies at 8 p.m. ET on Tuesday, providing the first public showcase of just how intense they plan on playing this season.