The Celtics’ postseason aspirations could not be more different from the Pacers’.

Back in the day, a coach in Rick Carlisle’s position may have given his squad a little pep talk — Pat Riley-style — about packing “three suits, three shirts, three ties” as they headed to New York for Sunday’s Game 7 against the Knicks. After winning Sunday, Indiana had to fly right to Boston for Games 1 and 2 of the Eastern Conference Finals, starting Tuesday (8 ET, ESPN).

No longer applies: Suits and ties on the sidelines went away with the COVID-19-caused Orlando “bubble.” One or two sets of fleece clothing may see a coach through an entire postseason, which has now become lengthier for Carlisle and his players.

The Pacers advanced to their first East Finals since 2014. They began the playoffs as the No. 6 seed, defeated Milwaukee and New York, and now face the conference’s leading challenger. Boston is making its sixth East Finals appearance in the last eight seasons.

The Celtics won the season series with Indiana 3-2, playing the Pacers five times due to the In-Season Tournament. Boston outscored Indiana by an average of 129.0 to 116.8 points per game, giving the Pacers their largest deficit (-12.2) against any opponent.

Don’t overreact to Indiana’s incredible shooting in the Game 7 win at Madison Square Garden. In five meetings with Boston, the Pacers shot 46.8% overall and 31.8% from deep, representing significant reductions from their 82-game average.

Series schedule

Here’s how to watch the Celtics vs. Pacers series: 

All times Eastern Daylight Time 

Game 1: Pacers vs. Celtics, Tuesday (8 p.m., ESPN) 

Game 2: Pacers vs. Celtics, Thursday (8 p.m., ESPN) 

Game 3: Celtics vs. Pacers, Saturday (8:30 p.m., ABC) 

Game 4: Celtics vs. Pacers, May 27 (8 p.m., ESPN) 

Game 5: Pacers vs. Celtics, May 29 (8 p.m., ESPN) * 

Game 6: Celtics vs. Pacers, May 31 (8 p.m., ESPN) * 

Game 7: Pacers vs. Celtics, June 2 (8 p.m., ESPN) * 

* = If necessary

Top storyline

Haliburton vs. Boston’s defenders. Haliburton, Indiana’s point guard and floor general, was publicly pushed to up his aggressiveness against the Knicks.

It worked. He averaged 24 points on 17.5 shots in the Pacers’ four victories compared to 17.6 and 11.3 in the three defeats.

“Aggression to me isn’t shots, it’s getting two feet in the paint,” Haliburton said Sunday.

OK, but the Celtics are a different challenge entirely. Remember, Boston and Indiana ranked 1-2 offensively this season, but 2-24 defensively. Haliburton’s production dipped in the four games he played in the series: just 15.8 points on 41% shooting (vs. 20.1 and 47.7% overall).

The Knicks found a few ways to contain him until they ran out of gas and healthy-ish bodies. Boston can send a fleet of defenders, starting with All-Defensive candidates Jrue Holiday and Derrick White. Then it has Jaylen Brown, Jayson Tatum and Payton Pritchard to shuffle through.

Indiana has to keep its pace high, because the Celtics’ half-court defense could choke off Haliburton and whatever offense he tries to initiate.

Keep your eyes on

Two pesky backup point guards. If Indiana is in the building (particularly its throwback style Fieldhouse), someone is thinking of “Hoosiers,” and Pritchard and T.J. McConnell seem straight off the cast list. They both are high energy and high impact, good for 15-20 minutes of caffeine boost.

Pritchard is making 42.9% of his 3-point attempts this postseason and is the Celtics’ designated last-ditch guy to race up court or throw heaves at the end of quarters. McConnell plays a similar role with Indiana and saw his minutes and contributions rise as he locked in defensively on Knicks star Jalen Brunson.

These guys’ greatest value comes when they log minutes pestering the opponents’ key players. But if their minutes match up and they simply go at each other, that should be entertainment too. Eventually, one or the other is going to speak up in the huddle and say, “I’ll make it.”

1 more thing to watch for each team

Could Pacers’ depth provide an advantage over the top-seeded Celtics until Kristaps Porzingis returns?

For Celtics: In terms of advancing, Boston did not miss Kristaps Porzingis against Cleveland, but it did lapse into some isolation-heavy offense as a five-out team. Getting their injured center back at some point in this series could restore order and help him ramp up for a potential Finals. Size will matter more against whichever team comes out of the West. Porzingis, out since Game 5 against Miami with a right soleus (calf) strain, isn’t expected to play in Games 1 or 2 this week, but could return deeper into this series.

For Pacers: Nesmith is the Pacers’ defender who typically draws the toughest individual matchup. Tatum is Boston’s top scorer, a guy who has finished Top 6 in Kia MVP balloting the past three years and somebody taking heat lately to up his consistency as a playoff performer. There is also an additional backstory. The two were teammates for two seasons after the Celtics drafted Nesmith at No. 14 in 2020. Nesmith is also the last key piece standing for Indiana from the 5-for-1 2022 trade that sent Malcolm Brogdon to Boston. Nesmith won’t be shutting Tatum down but timely disruption and minimal fouling could help the Pacers immensely.

1 key number to know

In 10 playoff games, the Celtics have experienced only 79 seconds of “clutch time,” when the score was within five points in the final five minutes of the fourth quarter. Nine of their ten games, including both losses, were decided by double digits.

Those 79 seconds of critical time came in Game 4 of the conference playoffs in Cleveland, when the Celtics led by nine points with five minutes remaining. The Cavaliers were within five points three times after that, but the Celtics scored six points on four crucial offensive possessions.

The Celtics ranked fourth in point difference per 100 clutch possessions (+15.4) in the regular season, but have not had many tight-game reps in the playoffs.Fourteen of the 16 playoff teams have had a game within three points in the last three minutes, with the exception of Boston and its first-round opponent (Miami).

The Pacers have won two out of four key playoff games, including two elimination games versus New York. Tyrese Haliburton struggled in four close games, hitting only 2-for-10 on crucial shots, including 0-for-6 from 3-point range. The Pacers won two of three regular-season games versus Boston, scoring 33 points on 22 crucial possessions in the final five minutes of each.

The pick

Celtics in five.Why five? The Celtics proved against Miami and Cleveland that they cannot sweep, no matter how well favored they are. It doesn’t matter how many. Boston is the team dealing with pressure here. It won 17 games more than Indiana this season and has been on the verge of a title for the most of the Tatum-Brown era. The Pacers, on the other hand, improved to 47 victories yet are only three years removed from a postseason drought. In this matchup, Boston triumphs because to its experience, depth, and urgency.