Irving at center of rivalry as Celtics, Cavs kick off season (Oct 17, 2017)

CLEVELAND — The last time Kyrie Irving played in an NBA game that counted, he was wearing a Cavaliers jersey.

The 2017-18 NBA season begins Tuesday night in Cleveland when the Cavs host the Boston Celtics. Check that — Irving and the Celtics.

Cleveland’s trade of Irving to Boston for Isaiah Thomas, Jae Crowder, rookie center Ante Zizic and two draft picks in August was the league’s blockbuster deal of the summer, and it adds considerable spice to the first game of the NBA’s season when the Cavs and Celtics tip at 8 p.m. ET.

The Cavs and Celtics were already the top two teams in the Eastern Conference — it was Cleveland, after all, that bounced Boston in five games from the conference finals last season. They seem positioned to meet there again in May, and perhaps for many Mays to come, depending on what LeBron James decides about his own future next summer.

All eyes will be on Irving come Tuesday night, but the larger and more important issue between the Cavs and Celtics is one that will play out over time: Has Boston closed the gap on James and the Cavs?

“Um (long pause). No, not really, honestly,” said Cavs guard J.R. Smith, as he ran through the major changes the Celtics made over the offseason. “Obviously there’s different people in different jerseys, but I mean, I don’t really pose them as a big threat to us.”

The Celtics added Irving, a four-time All-Star who averaged a career-high 25.2 points and shot a career-best 47.3 percent from the field last season. They also picked up Gordon Hayward, who averaged a career-high 21.9 points for the Utah Jazz last season, signing him to a four-year, $128 million free agent contract.

But to get Irving and Hayward into the fold and make the salaries work under the salary cap, the Celtics traded Thomas (a two-time All-Star, All-NBA selection, 28.9 points-per-game scorer) and Crowder, a coveted wing defender and 3-point shooter, to Cleveland. They also dealt Avery Bradley, perhaps the Celtics’ best on-ball defender, to the Detroit Pistons for forward Marcus Morris.

Together, Thomas, Crowder and Bradley made up most of the Boston core that pushed its way into the conference finals against the Cavs.

Cleveland not only added Thomas and Crowder, but also Derrick Rose (a former NBA MVP), Dwyane Wade, James’ best friend and 12-time All-Star, and former Celtic Jeff Green as rotation players. Thomas, However, has a right hip injury that is expected to keep him out for two months.

Oh, and James, a 13-time All-Star, four-time MVP who has gone to seven consecutive NBA Finals, and All-Star big man Kevin Love are still there.

“They have different pieces, obviously. There’s just one guy missing. That’s it,” Irving said, according to ESPN. “They added a lot of other great pieces they have on their team. And they’re running some similar things. But the playmaking as well that they have, that they utilize now, whether (James) is on the ball or whether Bron’s off the ball, they’ve got a point guard in Rose and a veteran in Jose Calderon, then of course guys coming off the bench.

“And, defense, raising the level of awareness out there, I mean, they have Jae Crowder at the 4 and Kevin Love at the 5. So that right there is a different framework than what I saw last year. So we’ve just got to get used to it.”

James sprained his left ankle in training camp, and coach Tyronn Lue said Monday he still didn’t know if the superstar would play in the opener.

Smith declared, emphatically, that James is “gonna go.”

“Trust me on that. I don’t care what he’s gotta do, he’s gonna play,” Smith said.

James has never missed a season opener in his first 14 years in the league.

The Celtics will start rookie Jayson Tatum and second-year player Jaylen Brown at the forward spots.

How will they react when the Cleveland crowd erupts in boos toward Irving in what is sure to be a highly charged atmosphere?

The Cavs are planning a video tribute to Irving, who made the game-winning 3-pointer in Game 7 of the 2016 Finals to hand the organization its first championship.

One summer later, he asked the Cavs to trade him. And here he is. Opening night. In Cleveland. Wearing a Boston jersey.

“It’s a huge game for Kyrie, and I think one we’re all looking to play our best for him, not only for the team but for him,” Hayward said, according to ESPN.