“It’s about to be crazy, G,” Irving said in the ear of Hayward to a soundtrack of clicking camera lenses as they sat on a dais back in September two days after Boston’s blockbuster trade with the Cleveland Cavaliers.

Seven months later, Irving has proven to be prophetic — albeit not how he had in mind.

It has been crazy unlucky for the Celtics. Stunning too. Al Horford said even shocking.

And though things haven’t gone as scripted in Boston, the Celtics will open the playoffs at the No. 2 seed in the Eastern Conference believing they can win it all without their injured offseason acquisitions.

“Finals. I’m very confident,” guard Terry Rozier when asked how far Boston can go. “Everybody has to be on the same page. And we just gotta play. And play hard.”

That’s been Boston’s calling card throughout the season. They have no choice but to play hard because from Hayward’s gruesome, season-ending left ankle injury on opening night, to the recent pair of left knee surgeries that has sidelined Irving, luck has been in short supply beyond the Celtics’ Leprechaun mascot named Lucky.

Horford acknowledged being shocked when he heard that Irving was done for the season. But he said the time has passed for sulking about misfortunes.

“We can’t dwell on the past,” Horford said. Obviously it makes it more difficult. Kyrie, he’s the leader of this team. We won with him and now we have to find ways to do it without him.”

In addition to Irving and Hayward, Boston will also be without productive rookie Daniel Theis (left knee surgery) for the season and Marcus Smart (right thumb surgery) until at minimum the second round. That’s not to mention a plethora of nagging injuries that have dogged the rest of the roster.

Yet, in an Eastern Conference that features a less-than-dominating LeBron James-led Cavaliers team, Boston veterans Horford and Marcus Morris and its corps of talented young players led by Jaylen Brown, Rozier and rookie Jayson Tatum give it as legitimate a chance as anyone to make it to the NBA Finals.

The Celtics will finish with their second straight 50-win season and their highest number of victories under coach Brad Stevens.

Last season as the East’s top seed, Boston made it to the conference finals in spite of being smacked with adversity on the eve of the postseason following the death of Isaiah Thomas’ sister. Thomas returned to the team, but was then lost midway through the conference finals to a hip injury he’d been quietly playing through.

“With Isaiah, we had him all year. Even though he was banged up, he was with us,” Horford said. “Now with our group this year it’s different. We’ve been having so many injuries throughout the year that I feel like our guys — we’re much more prepared handling everything that we’re going through.”

The good news is this Celtics team has already done an admirable job of figuring things out without Hayward and Irving.

They’ve played all but five minutes this season without Hayward. In 20 games without Irving they are 13-7.

Irving played his last game on March 11. That’s given Boston time to see what its remaining rotation will look like. One thing it will certainly mean is a lot more minutes for reserves like Shane Larkin and Greg Monroe, as well as rookies Semi Ojeleye and Guerschon Yabusele.

Stevens acknowledged that there was hope after Irving’s first surgery on his knee last month that removed a tension wire that he would be able to return early in the playoffs. Having him ruled out has “just solidified that this is where our focus needs to be” he said.

“It’s a great opportunity for the other guys and it’s our job to coach them,” Stevens said. “I believe in the guys in our locker room. They believe in themselves.”

Without Irving, the most glaring deficiency for Boston is its lack of a go-to scorer. Brown is just a few games removed from scoring a career-high 32 points, and Rozier only recently had a 25-game double-digit scoring streak stopped. He’s also proven to be a dependable defender.

Still, there is a sense in the East that Boston may be susceptible to a first-round upset. Miami and Milwaukee, currently have the same record (43-37) as the No. 6 and 7 seeds respectively. The Heat won 2 of 3 meetings this season with Boston, while the Celtics split their four games with the Bucks. Washington, at No. 8 leads the season series with Boston 2-1 with the series finale set on Tuesday night.

Vulnerable or not, Horford has a message for whoever their first-round opponent is.

“We’re the (No.) 2 seed. We have home-court advantage,” he said. “And this point, the only thing I can say to that is I can’t wait for the playoffs to start.”