Why Celtics’ gritty win vs. Rockets boosts Joe Mazzulla’s Coach of the Year candidacy

Less than 10 games into the 2025-26 regular season, the Boston Celtics were thoroughly embarrassed by the Houston Rockets. They fell 128-101 at TD Garden and dropped to 3-4 after getting outrebounded 53-36 and shooting under 40% from the field. Flash forward to Wednesday night, and the Celtics are fresh off destroying the Rockets in Houston without their two best players — Jayson Tatum and Jaylen Brown — active.

On the second night of a back-to-back, it was the Green Team’s turn to embarrass the Rockets, as the C’s grabbed a season-high 65 boards against one of the tallest starting lineups in the NBA. Boston also held Houston to its lowest scoring output since Jan. 15, and the 114-93 beatdown marked the Western Conference contender’s largest margin of defeat all season.

The Celtics' season-high rebound total is 58.

The Celtics already have 52 rebounds heading into the fourth quarter.

— Daniel Donabedian (@danield1214) February 5, 2026

So, what changed in those three months? It’s not like the Celtics got much taller or more talented in that span. In fact, the Celtics gave inexperienced guard Ron Harper Jr. the first starting nod of his entire career on Wednesday with Tatum, Brown, and part-time starter Sam Hauser sidelined.

How head coach Joe Mazzulla has improved the Celtics

But speaking of sidelines, that may be where the answer to this question lies. Celtics head coach Joe Mazzulla has helped transform a scrappy Celtics squad into an Eastern Conference contender that ranks third in offensive team rating and eighth in defensive team rating.

Simply put, Mazzulla is pushing the right buttons night in and night out.

Wednesday was a prime example of that because Harper Jr., who’s played less than 20 games in the NBA and is on a two-way contract, excelled in his starting role. The 25-year-old finished with a career-high 11 points in 33 minutes to go along with nine rebounds. His performance surely caused a lot of unfamiliar fans to Google his name, and it was another instance of Mazzulla placing his trust in the right people at the right time.

RON HARPER JR pic.twitter.com/cw5jMJsaW1

— Boston Celtics (@celtics) February 5, 2026

Just 24 hours before Harper Jr. wowed the Rockets, Mazzulla made another move that helped secure a win. On Tuesday night against the Dallas Mavericks, the fourth-year head coach moved point guard Payton Pritchard to the bench for the first time this season.

While some might expect this to throw Pritchard off his game, the reigning Sixth Man of the Year dazzled with 26 points off the pine on 60% shooting. Pritchard singlehandedly outscored the Mavericks bench and also dished out seven assists en route to a 110-100 victory.

Pritchard came off the bench again on Wednesday, recording 27 points and seven assists in 33 minutes of play. His win-at-all-costs mentality, paired with Mazzulla’s flexibility, is a recipe for success in Boston.

Why Joe Mazzulla should be Coach of the Year 

Mazzulla will never take credit for the Celtics’ winning ways, though. The five-time Eastern Conference Coach of the Month will always praise his players and staff first.

“Credit to the staff in Maine and here, getting all our young guys ready and then for us sticking together and being physical the whole f***ing game,” Mazzulla told the team in the locker room following Wednesday’s blowout victory.

Celtics player development program pic.twitter.com/s2ljia84BV

— Boston Celtics (@celtics) February 5, 2026

The New England native’s humble nature and refusal to prop himself up might not help him win Coach of the Year, but that doesn’t mean he isn’t deserving. Mazzulla has been instrumental in turning an 0-3 start to the season into a brilliant campaign in which the Celtics are 33-18 overall and shattering preseason projections.

The extended absence of Tatum led many to believe the C’s would falter this season, with some around the NBA world even suggesting that they tank without their go-to guy healthy. Mazzulla never bought into those low expectations. Instead, he used them as motivation.

“Everybody thinks we’re going to suck, I love it,” he told Celtics guard Derrick White back in July.

Months ago, Derrick White mentioned a call he received on his birthday from Joe Mazzulla.

He finally revealed what Mazzulla said:

“He’s like, ‘Happy birthday man…Everybody thinks we’re going to suck, I love it,’ and then hangs up.”

“And this is in July.”

@OldManAndThree pic.twitter.com/Aamo9jUtRc

— Daniel Donabedian (@danield1214) January 29, 2026

Although Mazzulla isn’t the frontrunner for Coach of the Year according to some betting sites, including BetMGM, he has as good a case as anybody. Detroit Pistons head coach J.B. Bickerstaff and first-year Phoenix Suns head coach Jordan Ott have more favorable odds, yet the former’s team didn’t have as low of expectations as the Celtics coming into the season, and the latter’s squad doesn’t own as good a record.

These two skippers have undeniably done a great job at the helm; however, neither had to reckon with a true championship core crumbling before them. The Celtics traded away two starters, had another injured, and lost multiple key pieces from the bench during the offseason.

In spite of this roster overhaul, the C’s have greatly overachieved and are in third place in the East. If the Celtics can usurp the top seed from the Pistons and sweep their season series with the Suns, Mazzulla will be the Coach of the Year in a just world.

However, the Pistons hold a five-game lead, and the Suns have been just as scrappy as the C’s. Regardless of what happens, Mazzulla doesn’t care about Coach of the Year. He just wants to create winning habits and instill confidence in his players — from the stars to the benchwarmers —  every step of the way.

“I think the best thing about this roster is each guy’s ability to impact winning in different ways,” Mazzulla said prior to a 107-79 win against the Milwaukee Bucks last Sunday. “And so it can happen whether you start, whether you come off the bench, whether you play five minutes, whether you play 20 minutes — every guy on this roster has helped us win a game.”

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