Celtics will be tested by Pacers and other thoughts on the Eastern Conference Finals

BOSTON -- The Celtics are about to encounter their biggest test of the postseason. The Boston defense is going to have its hands full with the fast-paced Indiana Pacers in the Eastern Conference Finals.

Still, the Celtics should win this series in five or six games and head off to the NBA Finals for the second time in the last three seasons. While the Pacers will pose the toughest challenge of the postseason so far, Boston has the superior team, better stars, a much better defense, and a seemingly clear path to return to the Finals. 

There is no denying that the Celtics are going to have to play much, much better than they did at times during their five-game series wins over the Heat and the Cavaliers. They were essentially "playing with their food" at times during the first two rounds.

The Celtics are going to have to be engaged from the jump each night in this series or the Pacers will run them out of the building before they have a chance to wake up. It wouldn't be any shock if this series goes a bit longer than Boston's previous two, considering the Pacers played the Celtics tough in four of their five regular-season matchups.

But do the Pacers have what it takes to win a best-of-seven against the Celtics? We'll see over the next two weeks, but that feels unlikely. However long the series goes, here's what we'll be watching for along the way.

The Pacers' absurd offense vs. the Celtics' stellar defense

Indiana owns the best offensive rating of the postseason at 121.7. Boston is second at 118.9. The Pacers also lead the NBA this postseason at 87.8 shots per game, getting 6.6 more looks than Boston this postseason. They lead the playoffs in shooting too, hitting 50.7 percent and 38.1 percent from three-point range.

They also lead the NBA in transition points during the playoffs, racking up 24.7 per contest. There isn't much the Pacers don't lead the NBA in offensively this postseason.

But the Celtics tout a suffocating defense and thus own a plus-12.8 net rating, which is the best in the playoffs. Defense is going to be the difference in this series, since the Pacers don't play any of it. So the Celtics will be able to get their points -- they just have to make sure the Pacers don't get theirs in bunches. 

Boston has allowed just 96.7 points per game this postseason, and kept the Heat and the Cavs under 100 points in seven of their 10 games. When the Celtics did allow the opposition to score more than 110 points, they lost both games.

The Pacers shot 46.3 percent and averaged 116.8 points per game against the Celtics during the regular season. The Boston defense is going to have to be at its best this series, and if it's not, the C's offense is going to have to do a lot to keep pace with Indiana.

Celtics-Pacers Stars and Studs

Supporting casts will certainly play an important role in this series. But the Celtics need stars Jayson Tatum and Jaylen Brown to really shine, and the good news is that they were at their brightest against the Pacers during the regular season.

Tatum absolutely torched Indiana, averaging 32.5 points over his four games against the Pacers. He did that on a ridiculous 57.8 percent shooting overall and 48.6 percent from downtown. And it wasn't just scoring for Tatum, as he averaged 11.0 rebounds and 5.8 assists per game. He also had a key block in the final minute of Boston's Jan. 30 win over Indiana at TD Garden, rejecting Myles Turner at the rim in a three-point game.

Brown was stellar as well, averaging 28.4 points over his five games against the Pacers. His overall shooting was even better than Tatum's at 60.6 percent, though he struggled from deep, hitting at just a 31.6 percent clip.

Now it's their time to shine in the Conference Finals once again. They have plenty of experience at this stage, and they are hungry to get back to the Finals. Get ready for them to feast on a non-existent Pacers defense.

If the Pacers opt to double either of the Jays, it will leave shooters open elsewhere. If Indy chooses to put a single defender on either, Tatum and Brown should put their heads down and attack the basket. If they do that, we're going to get a ton of new, glorious looking posters from the duo. 

Indiana also loves to send people to the free-throw line, and that should give the Celtics an edge -- so long as Tatum and Brown bring an attacking mindset into this series.

Tyrese Haliburton is the man in Indiana and is going to give the Celtics fits. It's just going to happen. He can do it all, as we saw back on Dec. 4 when he logged his first career triple-double in a 122-112 win over the Celtics in the In-Season Tournament quarterfinals. Haliburton's 26-point, 13-assist, 10-rebound effort knocked the Celtics out of the inaugural tourney, and the Pacers went on to lose the title game to the L.A. Lakers.

That trip to the In-Season final gave the Pacers -- and Haliburton -- loads of confidence for the road ahead. And they've certainly been playing like a confident team this postseason. Haliburton is coming off a series where he averaged 21.3 points off 53.8 percent shooting over his seven games against a tough (but battered) Knicks defense. 

The Other Guys

You can thank Jrue Holiday and Derrick White for keeping Haliburton mostly in check when Boston and Indy met during the regular season. The Pacers star averaged 20.1 points per game during his All-Star season, but just 15.8 against Boston. While he shot well against the Celtics, the Boston backcourt kept Haliburton from really taking over -- minus that In-Season Tournament loss. Expect White and Holiday to keep him wrapped up, while doing their usual thing on offense too.

In Indiana's five losses this postseason, Haliburton has averaged just 15.6 points and 7.2 assists. Containing him is the key to winning every night. The big debate that Joe Mazzulla will have on nights when Haliburton is feeling it is whether the Celtics are better off letting Haliburton get his while shutting down his supporting cast, or if they should still try to shut down Haliburton and hope his supporting cast doesn't go off.

The problem with that is that Haliburton's supporting cast is extremely capable of going off night to night. We saw that on full display in Sunday's Game 7 against the Knicks when Indiana shot a ridiculous 67.1 percent percent from the floor.

So far this postseason, the Pacers have seven guys averaging double digits in points per game. Haliburton hasn't even been their leading scorer, with Pascal Siakam leading the charge at 21.1 points per game. And we can't forget about the big man Turner, who has averaged 17.5 points per game for Indy.

The Pacers usually own the paint, so Al Horford is going to have to make the Indy bigs work until Kristaps Porzingis gets back, hopefully in Game 3. Horford is Mr. Fountain of Youth but Indiana's pace of play could really gas the soon-to-be 38-year-old.  Luke Kornet and Xavier Tillman could find themselves playing important roles early in the series as well.

The Other Other Guys

And then there is Aaron Nesmith, who shot 100 percent for the Pacers in Sunday's Game 7, going 8-for-8 for 19 points. He always has a chip on his shoulder when he plays his former team. He's a ball of energy that loves to throw himself around, and chances are he's going to do something to get under the skin of the Celtics. (And Boston fans too.) There will be a Nesmith revenge game at some point this series.

T.J. McConnell has been a thorn in Boston's side throughout his career, and he's probably going to help spark an Indy run or two off the bench. He averaged 9.5 points in his 18.5 minutes per game against Boston, shooting 54.5 percent of his shots.

You'll see a lot of comparisons to McConnell to Payton Pritchard, given that they both bring a ton of energy off the bench. But McConnell is not a three-point shooter at all, while Pritchard is never afraid to let them fly. The Celtics are going to need some big threes from Pritchard off the bench during this series, and some tough defensive minutes from Sam Hauser too.

REBOUND!

The Pacers lead the four teams still standing at 51.5 points per game in the paint, so trying to clean up on the glass is imperative for the Celtics. The good news is they lead the NBA at 35.5 defensive rebounds per game this posteason.

Indiana also struggled to keep the Knicks off the offensive glass last series, and have been giving up 11.2 offensive boards per game this postseason. On the other end, the Celtics are the best in the NBA at keeping opponents off the offensive glass, surrendering only 6.3 per game.

So that should be a point of emphasis for Joe Mazzulla's squad this series.

Brace yourself for a lights-out shooting game from Indy

It's going to happen. The Pacers are going to hit just about everything in at least one game this series. Given Boston's track record this postseason -- and the last few years -- chances are that will come Thursday night in Game 2. The series being tied 1-1 as it heads to The Hoosier State isn't completely unrealistic. 

It's going to be frustrating But don't freak out when that happens. Mazzulla has been a master at adjusting this postseason, and the Celtics should feel confident in their coach -- and themselves -- that the necessary tweaks will be made to continue their winning ways and advance to the NBA Finals.

It will be a bit tougher than the last two series, and potentially a lot more uncomfortable than anyone wants. The Celtics cannot try to sleepwalk through any of these games, because the Pacers will run them right out of the gym before they have a chance to wake up.

This will be a different kind of test for the Celtics. But it's one they should be able to pass, and one that will make them a better team for the road ahead.