The last time the Boston Celtics met the Miami Heat, Rajon Rondo’s left arm was a deflated balloon, the Celtics were limping to a 4-1 series defeat and the Lebron James-Dwayne Wade tandem was figuring out how to succeed against the NBA’s toughest defenses, a lesson the duo — and especially James — would infamously forget against the Dallas Mavericks in the NBA Finals.

Since then, a lot has changed. Danny Ainge revamped the entire Boston bench, the Heat dealt with a relatively quiet offseason, Erik Spoelstra met with Oregon Ducks football coach Chip Kelly to speed up Miami’s offense, expectations in Boston have been lowered, at least slightly, and Kris Humphries — helped (or hurt) by a marriage to Kim Kardashian that was shorter than Shaq’s shooting range — inexplicably took over from James as the NBA’s Most Hated Player.

After all that, the Heat and Celtics remain two of the Eastern Conference’s best teams, teams that have both a genuine respect and a bitter tinge of hatred for each other, both built during previous postseasons. The Celtics understand the Eastern Conference now goes through Miami. They know Miami was the better team last season, at least in the playoffs. They are entirely aware of how difficult a task stopping James, Wade and Chris Bosh can prove to be. But they would also like nothing more than to waltz into Miami tonight and steal a victory without Paul Pierce, not to mention shine a little bit of doubt on the growing feeling that this is Miami’s year.

Miami took a monster truck and ran it right over the Dallas Mavericks in the teams’ season opener, defeating Dirk’s boys by a far-worse-than-the-score-would-indicate 105-94 tally. It was a far cry from the way Miami started last season, when the team was hesitant and sloppy, clearly unsure of itself in the early stages of the Two And A Half Superstars era. Against Dallas, the Heat moved with a cohesive sense of purpose that wasn’t always evident last season, overwhelming the Mavericks with a fast break that broke like a tsunami and kept coming like bad Tyler Perry movies, displaying the swarming defense that was Miami’s best attribute last season while also showing the promise of an improved and devastating offensive attack. Miami’s win was Christmas Day’s most thorough performance, a beatdown that could not shake the memories of the 2011 NBA Finals but offered further hope that this year might be different.

Boston’s opening-day crusade was not nearly as thorough or as successful, but the Celtics can find solace in nearly defeating an improved New York Knicks team while Paul Pierce sat on the bench in a pin-striped suit. Despite the 106-104 loss, the Celtics will take a few positives from the Christmas Day affair: most importantly, Brandon Boss is a weapon off the bench, Rajon Rondo might have exchanged last year’s passivity for the aggressiveness of a pitbull (at least for the first three quarters) and Pierce should return at some point in the relatively near future, delegating Sasha Pavlovic back to where he belongs, on the bench (although some would argue he belongs elsewhere, such as at a men’s league near you).

The Celtics could very easily end tonight with an 0-2 record. Even if Pierce was at full strength, the Heat provide a fierce test, and I would rather jump out of a plane at an altitude of 25,000 feet with no parachute than think of Pavlovic defending James. Still, Rondo should be able to take advantage of Miami’s second-rate point guards, especially if he exhibits the same aggression he did in game one. Which is good: Boston could need another 30 and 10 from Rondo to surge past Miami.

It’s the rematch we’ve been waiting for. Rondo’s arm works again. James might be better than ever this season. Wade, as always, is destructive. Bosh vs. Garnett should be enjoyable like usual. Two of the Eastern Conference’s best teams are meeting at 8 p.m., and if it seems like their roles in this rivalry have changed since last year, that’s because they have. The Celtics now lay stationary in knee-high grass, staring down the front-running Heat from afar and hoping the opportunity to pounce will come.