Here are five keys to the Celtics-Heat playoff series

Butler also brings a certain swagger to the Heat. He is their tough, physical leader who never lets himself be overwhelmed by big moments. Regardless, the Heat always believes they have a chance. Here are five keys to the series:

1. Terry Rozier’s health

Rozier had a bit of a rocky start after being traded to the Hornets in January, but quietly found a rhythm. He shot 18.4 percent from the three-point line in February, 38.9 percent in March, and shot a blistering 58.6 percent in four games in April before being sidelined with neck spasms.

The Heat are notoriously vague about injuries and no timeline has been given on Rozier’s return. But the Heat will likely need the playmaking and shot creation of the former Celtics point guard to have a chance. Miami’s offensive rating of 113.3 is the second-worst among the 16 playoff teams.

2. The Porzingis Factor

Celtics executives have openly admitted that last season’s conference finals loss to the Heat really pushed them to acquire Kristaps Porzingis from the Wizards last summer. The Heat exposed the Celtics to a nasty defense that was a mix between zone sets and man-to-man schemes where they turned on screens at every position.

The Celtics didn’t have the big men capable of punishing a smaller defenseman for making a turnover. But the 7-foot-3-inch Porzingis is one of the best. He has been a post-up weapon for the Celtics this season, often catching the ball about 10 feet from the hoop, turning and simply firing over smaller defenders. He can also pull his man to the three-point line and cause damage from beyond the arc or cause confusion inside a zone.

In three regular-season meetings this season, the Heat played Porzingis more straight, without constant substitutions. It will be interesting to see if that was a look at their permanent approach or just playing skills in games that mattered less. Porzingis shot 57.1 percent from the field against the Heat this season and will be a focal point regardless of Miami’s plan.

3. Can Tyler be a hero?

Celtics coach Joe Mazzulla has done a masterful job of finding mismatches and ruthlessly attacking an opponent’s weak links on defense. Heat guard Tyler Herro, who missed last season’s conference finals due to a broken hand, will be Miami’s best offensive weapon in this series. But defensively he is a real liability.

Look for the Celtics to bring Herro into action time and time again, whether it’s chasing cross plays in transition or deliberately putting him into action in half-court sets. Herro simply doesn’t have the speed, strength or athleticism to slow down wings like Jayson Tatum and Jaylen Brown. Heat coach Erik Spoelstra is a master tactician and will do everything he can to hide Herro on that side of the floor, so it should be an intriguing chess game.

4. Quickly identify Heat’s X-factor

While Butler and Bam Adebayo are the undisputed leaders of this team, the Heat won last season’s series against the Celtics because of the contributions they received from unexpected sources, most notably Caleb Martin and Gabe Vincent. Martin came back down to earth this season, but will certainly be asked to do more without Butler. Vincent, Max Strus and Kyle Lowry are gone, and some of those minutes are now being filled by more inexperienced players like second-year forward Nikola Jovic and Jaquez.

Jaquez, who had 21 points, 6 rebounds and 6 assists in Friday night’s play-in against the Bulls, is probably best positioned to emerge as his team’s unlikely standout. Luckily for the Celtics, they have enough tenacious fullbacks to make everything a chore for him. They just don’t want him to gain confidence with a strong Game 1 outing.

5. Hit first

The Heat have been hanging around as a possible first-round opponent for the Celtics for months. Although the Celtics would never say it publicly, they were not excited about the prospect of this game. Butler’s absence reduces concerns considerably, but the Celtics must assert themselves at the start and leave no doubt as to whether they are the superior team.

The Celtics were just 1-3 at TD Garden in last season’s conference finals and 5-6 at home during the playoffs.

During this regular season, however, they scored a brilliant 37-4 at home. Furthermore, unlike some recent Celtics teams, they generally did a good job of not overlooking short opponents. The Celtics are by far the healthier team, and it’s no coincidence that they won 20 more games than the Heat. Finally, they won the season series 3-0.

Despite the history between these teams, there is plenty of reason to believe the Celtics need to end this series quickly.

Adam Himmelsbach can be reached at [email protected]. follow him @adamhimmelsbach.