Another chapter of the rivalry between the Philadelphia 76ers and Boston Celtics will be written in the 2023 NBA playoffs. The Celtics have unfinished business in the NBA Finals but the Sixers, tired of getting punked so early in the postseason, want more than anything to get past them and into the conference finals.

The Celtics and Sixers (not counting the times they were under their original identity, the Syracuse Nationals) have matched up 14 times in the NBA playoffs.

Boston has come out on top 10 times, including the two most recent times they matched up in 2020 and 2018. Joel Embiid carries a right knee injury into a series against a team that has had Philly's number better than anyone this season.

This writer's official prediction for the series is the Celtics winning in seven and Embiid missing at least one game.

But even with Embiid's injury, this iteration of the Embiid-era Sixers is better equipped than ever before to pull off the upset over their hated rival. Here are the five keys to making it happen.

5. Having James Harden and Tyrese Maxey score efficiently

With Embiid unlikely to command the offense as often as he usually does, the responsibility falls on his two co-stars to keep the offense going.

The Brooklyn Nets may be bad enough to beat when Harden and Maxey shoot a combined 10-38 without Embiid but these Celtics almost certainly won't be.

There's no sugarcoating how bad Maxey has been this season against Boston. Rather than being the microwave scorer that he typically is, he has short-circuited against Boston and its collection of tough perimeter defenders.

In order for the Sixers to have a good crack at the Celtics, Maxey has to break the dry spell. He has to take command of the offense when it needs a boost and make the opposing ball handlers work hard to get to their spots.

While Harden has fared better against the Celtics, he left a lot to be desired after the first round. He scored inside the arc with appalling inefficiency.

Bucking that trend against a team with as many tough perimeter defenders as the Celtics possess will be a tall task. He can overcome poor shooting from the field with free throws and playmaking.

The Sixers need him not to just stay afloat but carry the team while Embiid is hurt.

4. Keeping Tobias Harris in rhythm

The second round is usually where Harris' production takes a sharp decline as fans roast him for his bloated contract, treating one of the low-hanging fruits in the NBA like a piñata. Harris can't be invisible (or noticeable for his blunders) this time around.

Even though it came against an underqualified opponent, Harris had a great series in the first round.

Given his prior history under bright lights and the chasm between the Nets and Celtics' levels of talent and playoff experience, it doesn't feel like a precursor to his second-round performance. But it can be if Harris wants it to be.

Projected to spend a good amount of time guarding either Jayson Tatum or Jaylen Brown, Harris will have to be at his best on the defensive end. He has to keep his feet moving and contest everything when one of Boston's star wings stands in front of him.

On offense, Harris will have to be ready to be either a complementary sharpshooter alongside Embiid or a go-to scorer in the post without him. It's a lot to ask of him but it's what he has to do for the Sixers.

3. Recognizing and halting the hot hand

Aside from their opening night loss and a last-second, go-ahead triple in February, the Sixers have expertly kept Tatum in check. He averaged just 21.0 points per game against them, his worst average against any team this season.

His true shooting percentage of 52.3 percent against them is the worst against any Eastern Conference team.

The Celtics' safety blanket is surrounding Tatum with guys who know how and when to step up. Brown is the usual option to take over the game when his co-star isn't on one. But he is far from the lone guy.

On top of the unpredictable and havoc-wreaking Marcus Smart, the Celtics have two very good guards for whom the Sixers have not had many answers: Malcolm Brogdon and Derrick White.

All the efforts to slow down Tatum leave room for Brogdon and White to go off, which they have both done against the Sixers numerous times this season.

Brogdon brings crafty shot creation as a shooter and driver while White scores efficiently and plays fantastic defense. The Sixers have to keep Brown out of takeover move and account for the two stingy guards.

2. Countering the Celtics' five-out lineup

The battle of wits between Joe Mazzulla and Doc Rivers will be interesting to watch as each fan base pleads desperately that their coach screws up less often than the other.

How Boston uses its bigs — and how Philly responds — could have major implications for the series.

The Celtics' current starting lineup of Tatum, Brown, Smart, White and Al Horford roasted the Sixers' defense to the tune of a 129.2 offensive rating with its spacing. Drawing Embiid away from the rim offered up drive-and-kicks plays galore, netting a ton of open triples.

Defensively, the Sixers could go to a match-up/3-2 zone and put Embiid (or Paul Reed when Embiid isn't out there) nearest to the weakest shooter on the floor.

However, Philly's easiest route to beating that lineup is to simply let Embiid cook Horford, who doesn't have the juice to stop him anymore. But with the big man hobbled, that simple plan may not be as dependable.

Should Embiid be able to get enough going, it could implore Mazzulla to go bigger with one of the Williamses (Robert or Grant), which should give Embiid an easier assignment on defense. At the end of the day, all the tactics and lineup decisions rest on one gigantic factor.

1. Getting the most out of Joel Embiid as possible

Obviously, this last point is not as easy as it sounds. But it's still the biggest key for the Sixers: get the best version of the big man as his knee will allow.

Sadly, Embiid has been in this position before. Playoff injuries have been one of the most common occurrences in his career.

He has undergone treatment for his sprained LCL and seems to be staying as active as he can during practices and shootarounds.

All the good mojo from this season lies in the balance of his ability to play through the pain against one of the best rosters the NBA has to offer.

The good news for the Sixers is that the Celtics have tried a bunch of different ways to stop him to no avail. Horford's shooting makes his life tougher on defense, but his decline has allowed Embiid to make up for it on offense.

Using Grant Williams to guard Embiid just allowed him to fire up shots with ease. Putting Timelord on him doesn't guarantee success and, as previously mentioned, simply allows him to camp out in the paint, letting him conserve energy for the other end.

Embiid is obviously not 100 percent but pound for pound, this is the best he has ever been. His supporting cast is deeper than ever, and the team no longer looks totally lost without him.

The odds are heavily stacked against them. But these Sixers have what it takes to beat these Celtics.