Escaping TD Garden with a 100-99 victory over the Oklahoma City Thunder on Tuesday night does not make the Boston Celtics anything they weren’t before.

This win will not go down as some lasting referendum. It will not be a game the elders point to decades from now as the one that galvanized an improbable championship run.

In many ways, this victory isn’t anything too special. Really, it’s more like a loss that wasn’t.

The Celtics don’t emerge on top if Carmelo Anthony and Russell Westbrook don’t go 1-of-4 from the free-throw line down the stretch. And even then, they needed Marcus Morris to drill a one-dribble pull-up three to grab the victory:

Both sequences represent relative rarities. Anthony and Westbrook each entered the game shooting better than 73 percent at the charity stripe and a combined 64.6 percent in crunch time—not great, but also not miss-three-of-four-between-them bad. And fewer than 5 percent of Morris’ attempts this season have come as one-dribble treys. (To his credit, he’s shooting over 47 percent on such looks.)

If a few things go differently, the Celtics are beginning a four-game road trip talking about their fourth loss in five tries. This goes down as both a win and a near-miss. 

Yet, at the same time, it does mean more. Under the circumstances, it has to mean more.

The Celtics didn’t have Jaylen Brown, Kyrie Irving, Marcus Smart or Daniel Theis. They still don’t have Gordon Hayward. Theis is done for the season after undergoing surgery on a torn left meniscus. Smart is out indefinitely with a torn tendon in his right thumb. Brown is progressing through the NBA‘s concussion protocol, but that hardly masks perhaps the worst news of all: Irving’s left knee might be in worse shape than initially advertised.

Shortly before tipoff, league sources told Yahoo Sports’ Shams Charania the All-Star floor general will get a second opinion on his sore knee later in the week. He will not be joining the Celtics as they embark on their miniature road trip, and he still has no timetable for his return.

This latest development comes on the heels of team president Danny Ainge simultaneously delivering a murky outlook on the health of his point guard. 

“He has some surgery that may need to happen,” Ainge said during a recent appearance on 98.5 The Sports Hub’s Toucher & Rich show (via MassLive.com’s Jay King). “But maybe not this summer. Maybe the following summer or maybe the summer after that. I think that he could probably do it any time he wanted, but I’m not sure that it’s needed at this moment.”

Anxiety was tempered following these comments, if only because Ainge emphasized Irving’s apparently unavoidable surgery wouldn’t be taking place this season.

“We knew coming into this year that he probably wasn’t going to be an 82-game guy. He was going to be a 72-, 75-game guy in order to keep him fresh for the playoffs. And that’s what it’s been. And we’re just extra cautious. We have the good fortune of being extra cautious right now. And we want him fresh and healthy. And we think that he will be come playoff time.”

Perhaps this second opinion falls under the same umbrella—another extra precautionary measure by a team and point guard that can afford to take them. 

The Celtics aren’t catching the first-place Toronto Raptors without Irving. That’s fine. They weren’t overtaking them anyway. Five games separate the two teams in the win column, and the Raptors have not shown the faintest signs of loosening their chokehold over the rest of the Eastern Conference.

Forfeiting the No. 2 seed is equally unlikely. The Cleveland Cavaliers are within closest proximity, and they’re still seven wins off of second place. The Celtics and Irving have the luxury of slow-playing his recovery—or rather, his pain management—because there won’t be any repercussions. Their standing in the Eastern Conference is secure, no matter how impossible surviving without him may seem.

That’s precisely why this win over the Thunder can be seen as something more than just another victory.

OKC came into Boston winners of six straight, fresh off a Sunday upset of the Raptors in Toronto. The Celtics derailed that tear.

Sure, they needed a little luck on their side. But they kept things close through and through. The Thunder never led by more than 10 points, and the Celtics played them to a stalemate in the paint and on the break despite hosting an unsolicited turnover fest.

Reading too much into this lone outcome would be a mistake. One game is not the rest of the regular season. It sure as heck isn’t the playoffs. But this effort was an extension of the Celtics’ entire year—a microcosm of their depth in action.

As Action Network’s Matt Moore wondered aloud on Twitter (before getting unjustifiably mocked): 

This is a fair thought. The Celtics are not better off with Irving. He is their lone established isolation maestro and face-up killer with Hayward on the shelf.

Boston can’t rely on Al Horford for from-scratch buckets off the dribble with the game on the line, and Jayson Tatum isn’t ready to shoulder that responsibility yet. Irving is the foundation—the unparalleled lifeline—for everything the Celtics do and are capable of doing in crunch time.

That doesn’t mean they’re nothing without him. They aren’t. While Tatum isn’t comfortable enough working as the defense’s sole focus, he’s a scorer polished beyond his rookie-level experience. Greg Monroe gets buckets, period.

Boston still deploys plenty of switchable defenders even without Brown, Smart and Theis. Shane Larkin is playing the best basketball of his NBA career. Terry Rozier can shoot 5-of-15 from the floor, commit four turnovers and post tally a team-worst minus-16 and still make you believe he’s indispensable. Morris can play the part of effective self-sustaining scorer for possessions.

Horford, meanwhile, fits into any iteration of any team, shorthanded or otherwise. He is the Celtics’ trump card in these situations. He isn’t conventional, but he’s a star, and he isn’t unaccustomed to going it alone.

In the 600-plus minutes Horford has played without Irving this season, the Celtics are outscoring opponents by 9.6 points per 100 possessions—a carbon copy of the Golden State Warriors‘ league-leading net rating. That differential almost goes unchanged when you remove every one of Boston’s other injured players from the equation.

This isn’t a knock on Irving, because Horford isn’t alone. The Celtics are a plus-15.6 points per 100 possessions in the time Tatum has played without either of them, Brown or Smart. This team just works—and not by accident.

Head coach Brad Stevens is one of the league’s best tacticians, and he’s been gifted with one of the deepest, most malleable rosters around. What else should we expect?

Playing without Irving eventually will bite the Celtics. They’re a net plus without him on the season, but their offensive rating dips by more than eight points overall when he isn’t in the game. 

If his precautionary second opinion becomes a protracted stay on the sidelines that spills over into the playoffs, the Celtics will be vulnerable. They don’t have another go-to scorer who marries volume and efficiency in isolation. He averages twice as many pull-up jumpers as anyone on the roster and still owns the team’s best effective field-goal percentage on these shots among guards and wings.

Irving is irreplaceable in this sense. The Celtics will be held to a hard glass ceiling if he isn’t ready to rock in time for the postseason. But they’d also be far from a surefire first-round exit. They’ve played just well enough without him thus to grind out a series victory if the nightmare scenario plays out.

Which, above all else, is what makes them such a tantalizing contender through this season and beyond—not because of who they are at their best, but because of what they’re still equipped to do even when they aren’t. 

Unless otherwise noted, stats courtesy of NBA.com, ESPN.com or Basketball Reference and accurate leading into games on March 21.

Dan Favale covers the NBA for Bleacher Report. Follow him on Twitter (@danfavale) and listen to his Hardwood Knocks podcast, co-hosted by B/R’s Andrew Bailey.