BOSTON -- When Kristaps Porzingis finally fell asleep around 4 a.m. last Thursday morning, he still wasn't sure whether a trade to the Boston Celtics was going to take place.

The initial three-team deal Porzingis had believed would bring him to Boston involving the LA Clippers had fallen through. And, eventually, he decided he simply had to go to bed and leave his fate for the morning.

"It was a crazy day for me," Porzingis, seated between Celtics coach Joe Mazzulla and president of basketball operations Brad Stevens on a stage on the Auerbach Center practice court Thursday afternoon, said with a broad smile. "I was about to go to sleep, and then I heard the news that the trade didn't go through, so that kept me up for a little bit longer.

"But then by like 4 a.m. back home, I was like, 'OK, I'll go to sleep and see what happens.'"

What happened, it turned out, was that the deal did, in fact, get done, and Porzingis found his way to the Celtics in a three-team deal with the Memphis Grizzlies and his former team, the Washington Wizards.

"[When I woke] up in the morning, I saw that it happened, the trade happened," Porzingis said, "and I was just extremely excited and extremely happy."

Those two words -- "excited" and "happy" -- came up an awful lot during Porzingis' roughly 20-minute news conference Thursday. After spending the first eight years of his NBA career playing in a combined 10 playoff games -- and never getting out of the first round -- Porzingis made it clear he was thrilled about the prospect of joining a contender.

"[It was] an opportunity to play for a really good team already and be able to add to that," Porzingis said, when asked what went into his decision to pick up his $36 million player option to facilitate the trade happening. "And hopefully to help these guys, make their life easier, and being on a high-level organization like Boston, historic franchise, iconic franchise, it made it extremely easy for me to make that decision."

Porzingis, a 7-foot-3 Latvian, is coming off arguably the best season of his career. In 65 games during his lone full season with the Wizards, he averaged a career-best 23.2 points per game to go with 8.4 rebounds and 1.5 blocks.

It has been a bit of a roller coaster for him over the past few seasons. In 2019, he was traded from the New York Knicks to Dallas, where he was expected to be the second star the Mavericks were looking to pair long-term with Luka Doncic. Instead, it was a partnership that showed brief flashes of promise but ultimately ended with Porzingis being shipped to Washington at the 2022 trade deadline for guard Spencer Dinwiddie and forward Davis Bertans.

Porzingis said he has matured both physically and mentally over the past several years, and that he feels he's walking into a great situation as he approaches what he believes will be the prime years of his career.

"I think these are the best years for a basketball player," said Porzingis, who turns 28 in August. "You are physically there, and mentally, you are getting to a different level. I think the work paid off for me. I looked at my game, I looked at how I could be more efficient and just really analyzed myself, and it paid off last season, all the work I put in off the court to stay healthy.

"My body is maturing, and getting to that age helped, and I believe I have some great, high-level years ahead of me."

That's certainly what the Celtics are hoping and expecting will be the case, after landing Porzingis in a deal that involved trading away Marcus Smart, Boston's longest-tenured member and emotional leader as well as the NBA's Defensive Player of the Year in 2022.

Moving Smart for Porzingis represented a shift for Boston on several fronts. That's especially true on the heels of the Celtics losing in seven games to the Miami Heat in the Eastern Conference finals, after nearly coming back from a 3-0 series deficit. The most obvious and discussed aspect of the deal was losing Smart's voice from the locker room.

Stylistically, though, the deal represents a dramatic restructuring of the Celtics' roster. Boston's defense in recent seasons has often relied on having switchable defenders across the board, and for much of last season coach Joe Mazzulla leaned toward playing smaller, quicker lineups. Porzingis, while a strong rim protector, is not mobile enough to operate in such a scheme, and at 7-foot-3 is one of the league's tallest players.

Boston will look much different at the offensive end, as well. Smart has operated as the team's point guard for the past two seasons and was arguably the Celtics' best passer. And despite his preference for smaller and quicker lineups, Mazzulla made it clear he prioritized 3-point shooting. Porzingis, a career 36% 3-point shooter on 5.1 attempts per game, shot 38.5% -- the second-best percentage of his career -- on 5.5 attempts last season. He also was one of the league's most efficient post-up players, giving Boston a different look offensively in that manner, too.

"Just how he can take some pressure off of Al and Rob, how we can play double big, how we can continue to use Kristaps in the same way we used Al and how we can be better," Mazzulla said, when asked how he viewed Porzingis' fit with Boston's roster. "So, obviously with his ability to play out of the post, I think that will take some pressure off of our guys and give a different dimension to our offense."

The other theme Porzingis emphasized in his news conference was that he hopes to find ways to take pressure off Jayson Tatum and Jaylen Brown. He said he was looking forward to playing alongside them and taking advantage of the space they create by drawing so much attention.

"I want to come here to make life easier for those guys," Porzingis said. "Hopefully with my skill set and my talent I can take some pressure off of those guys. And that's it. I come here to try to make this team better. And I'm excited to play with such high-level guys that have been there from year to year and have that experience already. So, I think it can be a great combination."