Hang out around the Boston Celtics long enough, you’re sure to hear some version of the refrain: This team is different than last year. It has come up a lot this season and, in some way or another, during their first-round series against the Miami Heat.

Second-year coach Joe Mazzulla has spent most of the season fielding questions about Boston’s changes, how they managed to blitz the league for a season-high 64 wins, and if they can handle the pressure it all brings. Rather than deny the existence of that pressure, Mazzulla has spotlighted it.

“Yes, there’s pressure, there’s expectations,” Mazzulla said earlier this month. “But that will never go away.”

He’s right that pressure for title contenders doesn’t go away, but questions about whether they can handle it do – if they can prove that pressure isn’t debilitating.

This has been the critique of these Celtics during this run that has included four Eastern Conference finals and one Finals appearance over the last six seasons. Talent was never the question, nor was coaching until Mazzulla’s shotgun hiring before last season. Rather, the Celtics had an undeniable tendency to shrink in big moments. 

Whether they can rise to the occasion and overcome the pressure that they acknowledge exists remains an open question, even as the Celtics are up 3-1 over their rival Heat in the first round.

Here’s the rub: They may not be able to answer that question for a while.

Yes, the Heat have represented everything the Celtics are not over this last half-decade. The Heat: Mentally and physically tough… more than the sum of their parts… Culture™.

But this is not one of those Heat teams. Jimmy Butler, sidelined with a knee injury, is not a participant in what could have been another installment of this rivalry. Instead of a sequel, this series feels more like a spin-off featuring Miami’s budding young players.

The Celtics eliminating the Heat won’t represent the vanqishing of a demon they may have hoped. Neither would marching through a taped-together Eastern Conference as their top competition deal with their own significant injuries. The Bucks are dealing with an injured Giannis Antetokounmpo and Damian Lillard. Philadelphia’s Joel Embiid enters every arena with a laundry-list of ailments. The Knicks, without Julius Randle, will face serious questions about secondary scoring the further they go in the postseason. 

Whatever mental hurdles the Celtics hope to overcome may not present themselves until the NBA Finals. By then, they’ll be facing a team battle-tested through a tough Western Conference bracket.

All the Celtics can do until then is keep on with the positive self-talk. For sure, they have proven something by putting together the league’s top record and an all-time net rating that suggests they are nothing short of a title favorite. It’s enough to make onlookers wonder if this team really is different in Mazzulla’s second season.

“It just comes with time and it’s what we talked about all year when I get asked that question,” Mazzulla said when asked about the difference from Year 1 to Year 2 before Game 4’s blowout win in Miami. “It’s just a shared approach about how we’re doing it.”

The other difference is the roster. The Celtics traded Marcus Smart in a three-team deal to acquire Kristaps Porzingis, then added ring-holding champion Jrue Holiday to the mix. The Smart trade was polorizing. It’s always difficult to trade away the heart and soul of the team. But if the problem for the Celtics was their heart and soul – the thinking goes – then a violent shakeup may have been needed.

It worked. So did Mazzulla reflecting on his first season with Jayson Tatum and Jaylen Brown. After last season ended with a Game 7 loss to the Heat in Boston, Mazzulla sat down with his team leaders to talk about their vision for what their team should stand for and value.

“It comes down to building a relationship and building a shared mental model for how you want to approach things,” Mazzulla said.

If there was a bit of adversity in this first-round series, it might have been when the Heat went into Boston and stole Game 2. 

The surprising loss could be chalked up to the Heat making more than half of their 3-pointers, but Mazzulla and the Celtics were also critiqued for not making the necessary adjustments in real time. Soft closeouts to protect against drives to the basket led to what the Celtics called “dare shots” and the Heat catching fire. With the series tied 1-1, it would have been easy to say, Here we go again.

Only the Celtics made the simple adjustment of playing an under-manned team straight up. They scrapped the cutesy defense and let their overwhelming talent do the work. They have outscored the Heat by 44 points in the series and won every game that didn’t feature an outlier shooting performance by double-digits. This counts as adversity about as much as a trust-fund kid having to clean his own room because the maid didn’t show up.

Some real adversity may be on the way if Kristaps Porzingis, who hurt his calf in Game 4 on Monday, has to miss a substantial amount of time. The Celtics still cruised to a win despite the injury to Porzingis, who missed 20 games with various ailments throughout the regular season.

“That was the whole key throughout the season is developing different ways to play on both ends of the floor,” Mazzulla said. “So I thought the guys adjusted well to doing that, and I think that’s something we try to focus on; is regardless who’s out there we have different identities and the guys were able to execute that well in the second half.”

Despite their injuries, the Heat have countered by trying to muck up the series as much as they can. Bam Adebayo is landing punishing screens. Caleb Martin is giving hard fouls. The Heat are diving, deflecting and kicking up dust. Same song and dance from the teams’ past two Eastern Conference battles, just more of a talent disparity.

“Everybody knows how talented we are,” Tatum said. “Can we be the tougher, harder playing team? When you combine that with our talent level, I think it’s going to be hard to beat us.”

Here, Tatum is asking the very same question the NBA world has of the Celtics. Can they be the tougher, harder playing team? 

The Celtics know they have to be when, eventually, real adversity strikes. 

“The game favors the toughest team,” Mazzulla said. “Mental, physical, emotional, spiritual, whatever the toughness, the game favors that more than anything else.”