Green suede sneakers and genuine joy, that was what Kyrie Irving was wearing as he reintroduced himself to the basketball world as a Boston Celtic on Friday at TD Garden. His footwear and his excitement told the Celtics that Irving is as invested in them as they are in him.

The Celtics parted with a lot of their precious assets, including favorite son Isaiah Thomas, to get Irving. It was a bold move, just as bold as Irving deciding he no longer wanted to be LeBron James’s running mate in Cleveland and demanding to be traded. Irving and the Celtics have risked their reputations to be together. Their relationship has to work because they’re going to be judged on whether it ends up being worth it.

Irving, who was introduced alongside premium free agent acquisition Gordon Hayward, is unique on and off the court. He is going to be scrutinized here for his style of play and his speech. Kyrie is as much Kant as Curry. He is the philosophical point guard. That’s not always going to play well with the cynical sports-talk radio crowd.

But the only transcendentalism the Celtics are interested in is their belief that the 25-year-old Irving is the elusive transcendent player that can catapult them to legitimate championship contention. That’s why they tolerated Cleveland’s posturing and IT injury parsing, parting with a 2020 second-round pick Wednesday to close the anfractuous deal and make Irving the new Celtics centerpiece.

“Well, it’s very rare to be able to get a transcendent 25-year-old player in the NBA, a No. 1 pick in the draft,’’ said Celtics co-owner Steve Pagliuca. “[Celtics coach] Brad [Stevens] will tell you he’s maybe the best ballhandler he has ever seen — that’s saying a lot in the NBA — maybe him and Steph Curry. So, when you have a chance to do that you have to do that.’’

The Irving-Celtics marriage has to work because both sides sacrificed too much for it not to. The Celtics cashed in a portion of their enviable chips — Thomas, Jae Crowder, Ante Zizic, and a vaunted 2018 Brooklyn first-round pick — and traded with their biggest rival to bet on Irving.

Count me among those who believe Irving is worth it.

Kyrie left a situation in Cleveland where he was playing with the best player on the planet, won a championship, and had been to three straight NBA Finals to strike out on his own. He has a tough act to follow in Thomas, who gave his heart, his soul, and a tooth to the Celtics.

“Getting an opportunity to be a part of such an illustrious organization such as the Boston Celtics when you have the unique opportunity of being a part of an organization like this and they do everything possible in terms of putting themselves out there to make such a great thing happen you’re just appreciative,’’ said Irving. “I’m grateful. I can’t wait to get on the floor and to maximize my potential . . . I feel like in doing that Boston came right at the exact time, and it was meant to be that way. I trust in that, and I’m glad to be here.’’

The Celtics are trusting that Irving hasn’t reached his peak, that a player who shot 47.3 percent from the field last season, 40.1 percent from 3-point range, and 90.5 percent from the free throw line while averaging a career-high 25.2 points per game still has his best basketball ahead of him. His college coach at Duke, Mike Krzyzewski, co-signed that.

Pagliuca, a Duke grad whose sons Joe and Nick played for Coach K, was heartened when Krzyzewski gave the Irving-Celtics union his blessing.

“I’m happy Isaiah is going to a team where he has a chance to win a championship because he is a championship player, but I’m very sad that he is there,’’ said Pagliuca. “But at the same time, I’m excited that we got a guy like Kyrie here.

“Coach K actually called me as part of this process and said that he felt that Kyrie was almost just scratching the surface in Cleveland and that in a system up here with Brad Stevens, with letting Kyrie run the flow, that Kyrie was going to be even better than he was in Cleveland. If he is just as good as he was in Cleveland that would be amazing, so that was really heartening to hear that directly from Coach K.’’

Pagliuca said he never lost any sleep over the deal being in limbo while the Cavaliers expressed reservations about Thomas’s hip. He felt the deal was going to happen because “it was a win-win situation.’’

The Celtics tilled a team that was the top seed in the East last year to replant their roster. There are only four players from last year’s team who remain — Al Horford, Marcus Smart, Jaylen Brown, and Terry Rozier. That’s a lot of turnover. It transforms the Celtics from gritty overachievers to an All-Star-laden team with expectations as high as the Garden rafters.

Stevens sounded chary about the process of blending the talent and egos of Irving, Hayward, and nine other new faces. He understands the weight of the expectations playing for an organization that only hangs banners for NBA championships in a city that has been one big trophy room the last 15 years.

There’s going to be a lot of pressure on the upgraded Green to live up to the hype, especially Irving and Hayward.

“We’re all in this together,’’ said Irving, who will don No. 11 for the Celtics. “We understand that a lot of the responsibility of growing this team and making this team go will predominantly at times be on us, but at the same time we’re empowering our teammates and elevating them because this will get very real. We’ll be tested in a number of ways. I can’t wait. The fact that everyone is trying to put all this pressure on this team we just put together and we’re just incorporating ourselves into is step one.’’

Just like on the court, Irving always seems to have an answer. Irving is going to have to adapt his game. There will be fewer one-on-one forays. It doesn’t matter if Irving believes the Earth is flat, as long as he follows Stevens’s widely-endorsed round-ball beliefs.

Irving already has a championship ring and one of the biggest shots in NBA Finals history on his resume. But Boston is now his legacy place.

Both the Celtics and Irving got what they wanted, each other. Now, they have to prove it was worth it.

Christopher L. Gasper can be reached at cgasper@globe.com. Follow him on Twitter @cgasper.