Jrue Holiday’s life drastically changed before training camp this season. After three seasons in Milwaukee that included a championship, the veteran guard thought he would be a Buck for life. Then he was traded twice in the span of a week, sent to Portland before being rerouted to a preferred destination of Boston.

Holiday’s emotions were raw. He was disappointed he didn’t get a head’s up from Milwaukee that he was about to get dealt. But amidst all the chaos, his new home helped him feel at ease.

“The city of Boston, not only them but the organization made it super easy for us to have to navigate and get through a time that was a bit stressful for us,” Holiday said. “We love the city, we love this organization, the players in it, and what they stand for.”

It’s part of what led Holiday to sign a four-year, $135 million contract extension that was finalized on Thursday, keeping the All-Defensive guard in Boston through the 2027-28 season. It was a decision that mostly straightforward for Holiday, who soon turns 34 and recognizes the opportunity to win with these Celtics.

Jaylen Brown and Kristaps Porzingis have already inked extensions, and Jayson Tatum will likely earn the supermax extension this summer. The core of this championship-level team is set for the foreseeable future.

“I feel like it was pretty easy,” Holiday said. “I think mutually we just came to an agreement and felt like this was what was best for not only me, but for the team and, just hope it works. I want to be here. I want to win multiple rings. I’ve heard people say that here plenty of times, so I’m ready for that. …

“Once I got here, or even once I knew I was getting traded here, this was a part of what I wanted or what I envisioned. Being in a great organization, being here for a lengthy amount of time and being able to play along guys like JT and JB and really try to get more banners, get more rings.”

Celtics president of basketball operations Brad Stevens had long coveted Holiday and jumped at the chance to acquire him when the Bucks made their trade for Damian Lillard in September. Safe to say, Stevens has been pleased with how seamlessly Holiday has fit in Boston.

“In addition to being one of the more accomplished players in the league, Jrue is an elite teammate and competitor,” Stevens said in a statement. “He is simply a person who raises everyone’s level around him. He combines an unselfishness to do whatever is best for the team with an edge to take on any challenge at any time. We are grateful that Jrue is a Celtic.”

Holiday has made individual sacrifices as his scoring has dropped to 12.5 points per game – his lowest since his rookie season – and has seemed to adjust swiftly to his new situation. But there was certainly an adjustment period, one that was shorter than it may have typically been given the talent that surrounds him.

“I think there was a little bump there in the beginning, just trying to get my bearings in the city in general,” Holiday said. “But I think it comes pretty easy, just that type of guys that molds to my situation. And honestly, these players are really good. I think when you play with them, they make the game easy for you. This is probably one of the most that I’ve got so many open shots and just really trying to lock in and knock them down. So it’s been, like I said, maybe a little bit in the beginning, but it’s been pretty easy.”

There’s some relief for Holiday to get this deal done before the playoffs start, but he wasn’t losing sleep over it. He knew it would probably get done after the season is over. But after a whirlwind season, he’s happy to have some security on a team that’s set to win for years to come.

“It’s a blessing. This is my 15th year, I’m 33, I think that the opportunity that God has given me to be able to already play for this many years and then kind of lock it in for more, for me to be healthy and for our organization to see me and appreciate what I bring to the table is a blessing for me,” Holiday said. “At the end of the day, I am glad that we got it done before the playoffs. If it would have happened after, I still would have been happy. I still would have been locked in. But just really happy and really blessed.”

Tip-ins

Five of the Celtics’ top six rotation players – Tatum, Brown, Holiday, Porzingis and Al Horford – were initially listed as questionable for Thursday night’s game against the Knicks but all played. … Derrick White was the recipient of this season’s Red Auerbach Award, which is given to the player who best exemplifies the spirit and meaning of what it means to be a Celtic.