The first thing you noticed was the quiet.

Don’t get me wrong, it wasn’t a pall over the events at Knicks Media Day on Monday at the MSG Training Center. There were smiles and conversations. There was a collective good mood and the usual giddiness that comes with the start of a new season.

But as I stood in the gym among the players as they went through the various stations of photographs and interviews, I couldn’t help but notice the quiet.

“It’s definitely different,” Tim Hardaway Jr. said of the mood since he was last here three years ago.

Phil Jackson and the Triangle (and his tweets) are gone. Carmelo Anthony and his presence (and that storyline) are gone.

What is left is Kristaps Porzingis and the return of his quick smile and engaging personality, which went missing late last season in the most alarming moments for the franchise. Before I even asked him how he felt, physically, after a summer of hard work, I asked him how he was “up here” and pointed to my head.

“I’m good,” he assured me. “It’s good.”

He did offer a pause earlier in the day when he met the media outside and was asked if he felt the franchise was now headed in the right direction. Remember, the reports were that the reason behind his decision to skip his exit interview with Jackson at the end of the season was based on his disillusionment with where the Knicks were headed.

“Uhhh,” the 22-year-old said as he considered the question.

“I believe so, I believe so,” he then said. “I have faith in those people [in the front office] and I believe they want us to grow and they want for me to be in a position so I can succeed. I’m excited … A lot of new things are happening and a lot of new people are here. So it’s going to be a lot of changes. I’m coming in with a fresh mind.”

Scott Perry, the new general manager that represents the most significant change since KP left for the summer, spoke directly about Porzingis as a player who will need to set the standard for the franchise. KP can’t only show he a willingness to replace Melo as the team’s star, but also a willingness to be coached and, most importantly, to be fairly scrutinized.

“We want to see that natural progression,” Perry said of Porzingis. “We’re going to support him, push him, we’re going to hold him accountable. And ultimately he’ll determine how much he’s going to be able to handle as far as the leadership role. I know he’s looking forward to the challenge.”

He spent the entire summer away to clear his mind and to prepare for this next step in his career. Just one look at him and you can clearly see the evidence of a determined offseason. When he first arrived as a rookie, Porzingis was thin and had that typical forward lean of an awkwardly tall, bony frame. Two years later, his back is broad, his shoulders muscular and his chest is back.

[For those looking for big legs or biceps, don’t bother. This is basketball. Shooters don’t want big arms. As for legs, he spent a lot of time on them, but as a fellow skinny-leg guy, there’s only so much you can do. The rest is the result of genetics.]

Overall, Porzingis looks solid and feels physically confident. He got to try out his new body playing for Latvia at EuroBasket earlier this month and was happy with the results. He’s also curious to see how it rates against NBA players.

“I don’t know if I’m stronger or the guys I played against were just not strong,” he said. “But I feel strong.”

The franchise now rests on these shoulders. #Knicks A post shared by Alan Hahn (@ahahnmsg) on Sep 25, 2017 at 11:34am PDT

He will miss Melo, there’s no question about that. Defenses will pay more attention to him now than ever before. He added a terrific post move that could become an unstoppable weapon in mid-post isolations — an inside-pivot step out of the catalogues of Dirk Nowitzki and Melo — and continues to spend a lot of time on his catch-and-shoot threes as a trailing big on the break. Leg stability and endurance was a focus this summer and that will have a direct impact on his shooting percentage late in games.

And then there’s the weight of expectations now from media and fans in New York. It’s inevitable. The clock starts now for him. Heavy is the head that wears the crown in this city.

“I’m excited about the opportunity to be a leader of the team,” he said. “At the end, it’s not just one guy. It’s going to be us 15 guys as a team. But I’m excited about being one of the leaders of the team.”

MEDIA DAY NOTES

– I had a great chat with Hardaway Jr., who is back to the kid I remember early in his rookie season. He admitted that he had some maturing to do and it happened when he went to the Hawks and they sent him to the D-League.

“You start to realize the opportunity you have and you don’t want to throw it away,” he said.

I asked him why — aside from the contract, of course, did he want to come back to New York, knowing what he went through the first time around.

“I wanted the challenge of proving myself. I’m not the same player or person that I was when I left.” It’s great to see the confidence back in his eyes. Last time I saw him in a Knicks uniform, he had shut down emotionally.

– More on jersey numbers: Enes Kanter chose jersey No. 00. Meanwhile, rookie free agent signee Jamel Artis went with No. 0. No player has ever worn 00 in Knicks history. Artis would be the fifth player to wear No. 0, however. Shane Larkin was the last in 2015. Larry Hughes (2010), Earl Clark (2014) and Chris Smith (2014) are the others.

– Perry addressed the fact that the Knicks have three centers on the roster right now in Kanter, Willy Hernangomez and Joakim Noah. “A lot of things will be sorted out through training camp,” he said. He also added that the minutes “will be decided how guys compete.”

But will all three still be on the roster by opening night? Perry admitted he may not be done making moves.

“Part of my job is to daily assess our roster and take phone calls and figure out ways to keep getting this basketball team better,” he said. “So I will continue to do that.”

– Noah, who played just 46 games last season, was notably subdued when he talked to the media.

“I’m in a position right now where I had a really rough year last year. I’m coming off injuries and I just want to redeem myself for myself, more importantly, more than anybody else,” he said.

“Just come back and — look I got paid a lot of money to be here and I just want to be at peace with that.”

Noah signed a 4-year, $72 million contract last summer, but dealt with hamstring, knee and shoulder issues throughout the season. He was suspended 20 games in March for violating the NBA anti-drug policy after he tested positive for some over-the-counter supplements. He served the first 8 games at the end of last season and will sit out the first 12 games of this season.

– First round pick Frank Ntilikina spoke confidently about starting his NBA career. I loved what he said about his process of development: “I say every rookie needs to work on his potential and his abilities,” he said.

“It might take time. I will do the best for the team and for me to make this time to be as short as possible.”

– My favorite of the many conversations I had from the day was with Hernangomez, who, like Porzingis, clearly put in a lot of work on his body during the offseason.

Hernangomez, a rebounding machine for Spain at the EuroBasket tournament, looks more muscular, but I couldn’t help but notice him seeming taller than last season. He told me last year he measured in at 6-foot-10. He had not yet been officially measured by the team, but proudly told me at EuroBasket, “I measured 6-foot-12.” He smiled.