The Boston Celtics’ hopes of getting All-Star point guard Kyrie Irving back in the lineup in time for a deep postseason run went up in smoke on Thursday.

Twelve days after the Celtics announced that Irving would return to basketball activities in three to six weeks following a surgical procedure to alleviate persistent discomfort in his left knee, ESPN’s Adrian Wojnarowski reported Thursday morning that Irving “will miss the rest of the regular season and playoffs” in the aftermath of the procedure.

Shortly thereafter, the Celtics confirmed the devastating news, offering an initial timetable that suggests what was first described as “minimally invasive” knee surgery wound up being something more maximal:

From the Celtics’ announcement:

Irving weighed in on the news on Instagram, expressing his disappointment at being taken off the board before he could embark on his first postseason in kelly green.

“The hardest thing to do sometimes is accept the uncontrollable things life throws at you,” he wrote in the caption of his post. “You try consistently to learn, grow, and prepare everyday to equip your mind, body, and spirit with tools to deal with some of those things, but I feel when those moments arise they all give you a sense of unfulfillment, simply because it puts some of your professional journey and goals on a brief hold. It’s simply a test of your perseverance and Will, to be present, even in the wake of what’s going on.

“In this case, finding out I have an infection in my knee is definitely a moment that I now accept and move past without holding on to the all the what ifs, proving the nay-Sayers completely f***ing wrong, and accomplishing the goals I’ve set out for the team and myself,” he added. “This season was only a snapshot of what’s to come from me. Trust Me.”

This, to put it mildly, deals a massive blow to the postseason hopes of a Celtics team that has ranked at or near the top of the Eastern Conference all season long, and that has boasted one of the NBA’s premier defenses throughout the campaign, but has often struggled to generate consistent offense without Irving’s elite ball-handling and shot-creation skills.

The Isaiah Thomas-helmed iteration of the C’s had already proven capable of winning a bunch of regular-season games and getting through to the Eastern finals, but didn’t have the firepower to stand toe-to-toe with LeBron James’ Cleveland Cavaliers, the bully on the block and the dominant force atop the conference. That’s why Danny Ainge shelled out a maximum-salaried contract for All-Star forward Gordon Hayward back in July, and why he pulled the trigger on the late-August blockbuster trade shipping Thomas, forward Jae Crowder, rookie center Ante Zizic and the Brooklyn Nets’ unprotected 2018 first-round draft pick to Cleveland in exchange for Irving.

Kyrie had made it clear that he no longer wanted to be in LeBron’s shadow, and yearned for the opportunity to strike out on his own, broadening his horizons on and off the court and looking for a chance to lead his own team into the postseason crucible in pursuit of glory. Ainge saw an opportunity to replace two troubling questions — what sort of player Thomas would be after his season-ending hip injury, and how Boston would handle his impending free agency — with a younger, bigger answer who’s already demonstrated a capacity to make magic against the best defenses the NBA could offer come the Finals, and to take one of the Cavs’ legs out in the process.

The Celtics lost one of those marquee additions on opening night. Now, nearly six months later, with just three games left in the regular season, they’ve lost the other, a crushing subtraction that could transform reeling Boston — still without the rehabbing Hayward, also without top reserve guard Marcus Smart through at least the start of the playoffs, and without rotation big man Daniel Theis — from a potential conference finalist into a team on upset alert in Round 1.

Irving hadn’t played since halftime of the Celtics’ March 11 meeting with the Indiana Pacers, exiting due to the left knee soreness that flared up during Boston’s March 3 loss to the Houston Rockets and that had kept him out of a March 6 win over the Chicago Bulls. Irving returned to the lineup two nights later, collecting 23 points, eight assists and seven rebounds in a victory over the Minnesota Timberwolves, but he evidently felt discomfort throughout that first half against Indy.

That led both player and coach to decide discretion was the better part of valor when talking about an ailing body part that, lest we forget, was fractured less than three years ago. From Jay King of MassLive.com:

Celtics coach Brad Stevens, too, seemed confident that a little bit of caution and rest would clear things up, according to Chris Forsberg of ESPN.com:

To that end, this outcome is in keeping with the Celtics’ commitment to “prioritizing [Irving’s] long-term health,” which makes a lot of sense when you’re talking about a just-turned-26-year-old who’s under team control for next season before reaching a $21.3 million player option for the 2019-20 campaign, the final year of his current contract. It is also, though, a handy reminder that whether or not a procedure is “minimal” really depends on which side of the knife you’re on:

With Thursday’s bombshell now delivered, the Celtics and the rest of us are left to sift through the dust it kicked up.

Ever since he moved from Butler to Boston, Stevens’ flowing offensive system has been a rising tide that’s lifted all boats, but it still needs a dynamic captain at the controls, one capable of turning the possibilities it creates into points. And besides, there comes a point in the playoffs when the other guys have you scouted dead to rights, and they know where you’re going just as soon as you do, and what’s your first read after that, and what’s the second option on the backside of the play if it all blows up. At that point, you’d better have a teleporting locksmith with a ratchet and the confidence to go get the buckets that need to be gotten.

The Celtics thought they had theirs. Now, Boston will enter the postseason without its leading scorer, its top assist man, its highest-volume 3-point shooter (and its third most accurate, at 40.8 percent from deep) and its most reliable generator of free-throw attempts. When they find themselves in close games late in the fourth quarter, they figured to rely heavily on Irving’s one-on-one brilliance and shot-making talent; now, Stevens and company will have to figure it all out without the NBA’s third-most prolific clutch-time scorer.

This season, in non-garbage-time settings, the Celtics have scored 111.7 points per 100 possessions with Irving on the floor, and 102.9 points-per-100 with him off it, according to Ben Falk’s numbers at Cleaning the Glass. Put another way: with Irving in the game, Boston has scored at a rate nearly commensurate with the league-best offenses in Houston, Golden State and Toronto. With him off the court? They’ve produced like the dead-last, No. 30-with-a-bullet Phoenix Suns.

And that’s during the regular season, before we get to a playoff scenario in which you’re typically facing off against superior defenses, in which opposing players and coaches get to game-plan specifically against you, and in which the ability to improvise in isolation becomes one of the most valuable tools a player can have. Few players in the league can match Irving’s talents in that particular realm. No healthy member of these Celtics can even come close.

That doesn’t mean we should be penciling them in for a first-round washout, though. The defense has continued to play, even as Boston has turned into a M*A*S*H unit over the past few weeks. With Irving and Smart sidelined, Terry Rozier has been a revelation, averaging nearly 17 points, six rebounds and five assists in 34 minutes per game while shooting 40 percent from 3-point land over his last 10 games. Boston can still run stuff through ostensible point center Al Horford. Jayson Tatum has scaled the rookie wall and looked largely dynamite since the All-Star break. Marcus Morris has come on, and Jaylen Brown has started to come back. There’s talent here, shooters and finishers who execute, and long-limbed pests who can turn defense into offense to help the Celtics keep plugging away.

Even so, though, you’d expect the Miami Heat, Milwaukee Bucks and Washington Wizards — all separated by just a half-game in the race for 6-7-8 in the East — to think long and hard about what they’ve got to do over these last few days to finish seventh and sign up for a trip to Boston to open Round 1. The Celtics were already wounded. Irving’s injury all but assured that they’re now mortally so, leaving only the question of when they’ll fall, and what kind of hell they can raise before they do it.

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Dan Devine is a writer and editor for Yahoo Sports. Have a tip? Email him at devine@oath.com or follow him on Twitter!

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