TV: ESPN, 8:30 p.m. ET
BetMGM line: Celtics -2.5
How we got here
Game 1: Celtics 107, Heat 118
Game 2: Celtics 127, Heat 102
Game 3: Heat 109, Celtics 103
Game 4: Heat 82, Celtics 102
Game 5: Celtics 93, Heat 80
Game 6: Heat 111, Celtics 103
3 Game 7 storylines
It has been a wildly uneven series replete with injuries, but the Eastern Conference finals is all square heading into Sunday, with the Golden State Warriors lying in wait for the winner in the NBA Finals.
The Heat gutted out a Game 6 win to get one shot at a second Finals in three years, while the Celtics are trying to make the terrifying transition from "promising future" to "elite present" after years with their current core. The Heat, the No. 1 seed in the East, will host, while the Celtics are favored.
Here's what we'll be thinking about at tipoff.
Which Jimmy Butler will show up?
Let's throw out how many points Heat star Jimmy Butler has scored in each game of this series: 41, 29, 8, 6, 13, 47. He has averaged 24 points per game with a standard deviation of 16. You can get more harmonious numbers from a random number generator.
So that might be the big question for the Heat. Butler played the hero and then some Friday, but he has also had games in which he completely failed to break Miami out of an offensive slog. The Heat brought in Butler three years ago to be their guy in the big moments, and a Game 7 to reach the NBA Finals certainly qualifies.
Butler has long occupied an interesting position in the NBA landscape. He isn't a face of the NBA like some other players in these conference finals, which is more a product of the frustrations at his previous stops and the maniacally team-first ethos of the Heat, but he is most certainly among the players you should be terrified to see leading your playoff opponent.
Are Celtics' young players ready for the moment?
Jayson Tatum, Jaylen Brown, Marcus Smart, Robert Williams, Derrick White, Grant Williams. None of these players are older than 27, but none of them are younger than 23. The time for actual winning has come.
For as talented as the Celtics are, it's hard not to look over and see a Heat team with the kind of experience you want for a game of this magnitude. Much of the team's rotation remains from when they reached the NBA Finals in the bubble, and Kyle Lowry still has that ring from his time with the Toronto Raptors.
Then again, the Celtics reached this round via a Game 7 win in which they smothered the defending champion Milwaukee Bucks. There has been so much to like about the Celtics' future for so long and this may be the first time in which the team feels like it is playing to its actual potential.
Win, and you're looking at a long-awaited Finals debut for this group.
Just how healthy are the Heat?
The biggest X-factor going into Sunday's game is whether or not NBA Sixth Man of the Year Tyler Herro will be suiting up. Herro has missed the past three games of the series with a groin strain. On a related note, the Heat have averaged 91 points in those games after scoring 109.7 points per game in Games 1-3.
Herro is reportedly in "wait and see" mode for Game 7 with a workout on Sunday to determine his availability. Miami could certainly use his scoring.
The other major question mark for the Heat is whether Lowry can get anywhere close to 100 percent. The veteran point guard has been difficult to watch since returning from a hamstring injury in Game 3, averaging 8 points per game while shooting 27% from the field. He had his best performance in Game 6 with 18 points and 10 assists, though he still missed nine of 14 shots.
The Celtics haven't been injury-free either, with Smart and Williams both questionable for Game 7.