Though San Antonio currently has one of the best records in the league, it is fresh off its second loss to the Los Angeles Clippers and has posted a record of 1-3 against teams over .500 this season.
Boston hasn't done any better. Rajon Rondo and company have lost two of their last three, including a blowout failure dealt out by the lowly Detroit Pistons.
It's still early in the season, but these two veteran squads were supposed to be near unbeatable contenders from the get-go. But that hasn't been the case.
Which means the path back to prominence leads through this game.
For one of them.
Time: Wednesday, November 21st, 7:30 p.m. ET
TV: NBA League Pass
Records: Boston Celtics (6-5), San Antonio Spurs (8-3)
Betting Line: Spurs -1.5
Injuries (via CBSSports.com)
Celtics: Avery Bradley (shoulder), out; Paul Pierce (ankle), questionable.
Spurs: Stephen Jacks (hand), out; Kawhi Leonard (knee), out.
Key Storyline: Could this be the beginning of the end for the Spurs?
Much to the chagrin of the masses, San Antonio has been counted out before, only then storm into the season and completely dominate.
And yet, despite winning eight of its first 11 games, Gregg Popovich's team suddenly seems, well, vulnerable.
Not only have the Spurs posted a losing record against winning teams thus far, but they're now down Jackson and Leonard, two vital cogs in this fundamentally sound machine.
With Manu Ginobili and Tony Parker's production wavering, can Tim Duncan keep carrying this team toward prominence? Or is the era of dominant San Antonio basketball over as we know it?
We'll know a great deal more once we see how well—or poorly—the Spurs fair when matched up against an equally hungry Celtics team.
Key Matchup: Kevin Garnett, PF, Celtics vs. Tim Duncan, PF, Spurs
It says power forward next to both Garnett and Duncan's name, but—even with DeJuan Blair starting these days—this is really a battle of two centers.
Garnett has played stellar basketball all season long. He's averaging over 15 points and seven rebounds per game while posting a PER of 20.25.
Though the big man has not been able to solve Boston's rebounding deficiencies, he has become a consistent source of offense—shooting 51.2 percent from the field—and remained a formidable defender as well.
That said, he's going to have his hands full against an ageless peer in Duncan.
Duncan is averaging another double-double at 18 points and 10 rebounds per contest, posting an obscene PER of 27.53. He's also swatting away 2.7 shots a night as well.
While many people will have their eye on the Parker-Rondo bout, this one is going to have a bigger impact on the game.
Neither player has the clear edge, rendering one's ability to outdo the other, a factor that ultimately plays a significant role in determining the outcome of this game.
Leandro Barbosa, SG, Celtics
Unlike the Spurs, the Celtics are anything but deep at the point guard.
Jason Terry has the ability to run some point, but Barbosa has emerged as a capable stopgap as well. Boston will need for him to continue to bring some structure to the second-unit when Rondo is on the bench.
Patty Mills and Gary Neal are two underrated talents in the backcourt who ensure San Antonio doesn't miss a beat when Parker heads to the bench.
Barbosa's ability to do the same for the Celtics will give them a much better chance at handing the Spurs a fourth loss against an opponent with a record of .500 or better.
Gary Neal, PG, Spurs
Speaking of Neal, he is just as important to San Antonio's game plan as Parker is.
Prior to injuring his ankle, Rondo was averaging over 40 minutes per game.
He doesn't sit much, which means the Spurs' backups in the backcourt—most notably Neal—will see plenty of time up against him.
Neal's ability to protect the ball on offense and impede Rondo's court vision on defense will go a long way for spelling gloom or doom for San Antonio while in Boston.
Courtney Lee, SG, Celtics
The Spurs are going to put their best perimeter defender on Paul Pierce. End of story.
Or is it?
Jackson and Leonard, two of San Antonio's best defensive players, will be on the shelf for this one, leaving Danny Green to tend to Pierce.
In theory, this should open things up for Lee, who will spend time being defended by Manu Ginobili, among others.
With Pierce, Rondo and Garnett's hands full against the likes of who the Spurs combat them with, Lee won't have to go up against any of San Antonio's top defenders. Which means he needs to have a big night.
If the Celtics want to ensure they walk away with a victory, that is.
Manu Ginobili, SG, Spurs
San Antonio lost over 18 points in total offense when it had to relegate Jackson and Leonard to the sidelines.
The once potent scorer's production has tapered off quite a bit this season. He's averaging just 10.4 points—the second lowest total of his career—on a career worst 40.3 percent shooting.
That said, Ginobili has put up 15 or more points in each of the last two games, outputs he'll have to match if San Antonio wants to come up with a big win on the road.
Prediction: Celtics 99, Spurs 96
This one is going to be close, but it should ultimately fall the Celtics' way.
The Spurs are simply too depleted at this point—even for them. They're one of the deepest teams in the league, but Jackson and Leonard are two key pieces to the puzzle that they cannot replace.
I'm also not thrilled with the play of Ginobili or Parker for that matter. Ginobili has injected some extra pep in his step over the last two games or so, but Parker has been relatively quiet since his late game heroics over the Oklahoma City Thunder.
Understandably, Boston is a team in turmoil. Its not rebounding at a high rate or scoring at a high rate, but neither are the Spurs. Plus, on what has become a rarity, the Celtics' bench doesn't appear over matched in this one either.
Expect Rondo to carve up a suddenly porous perimeter defense and keep his streak of 10-plus assists alive. And while both Pierce and Garnett may struggle to score and defend against Green and Duncan, this game has the makings of a Lee and Terry explosion.
No, the Celtics have not played dominant basketball by any means this season. But I simply cannot go against a team as thirsty to prove themselves as they are at this juncture.
Especially when they're going up against a Spurs team who has been ever so gently knocked off their pedestal.
All stats in this article are accurate as of November 20th, 2012.