Doc Rivers started Tuesday’s film session showing every Game 1 layup the Miami Heat made on loop. It was the coach’s way of telling his players they’d performed with a certain softness and lack of purpose that he didn’t find acceptable. But Rivers only called out one player’s physicality by name — Paul Pierce. (WEEI)

“It’s easy to read if he has no foul shots and only two rebounds, then it wasn’t a physical game for Paul,” Rivers said. “Paul is every bit as physical as LeBron as far as body types. He just has to do it.”

So many other things went on Monday — Rondo’s uneven play, KG’s thorough dismantling of Miami’s front line, Ray’s continued struggles, Lebron laughing at KG, Rondo hoping the Heat would “hit the deck” in Game 2 — that Pierce got a relatively free pass for an abysmal showing. He scored 12 points on 18 shots, didn’t manage to earn a single trip to the free throw line, finished a team-worst minus-16, allowed James to go wild (which admittedly isn’t entirely Pierce’s fault — James, after all, is a mutant ninja hooper engineered specifically as a basketball prototype), and corralled only two rebounds (compared to James’ 13) in 40 minutes.

The Celtics don’t need Pierce to outplay James (fat chance of that happening, anyway), but they do need him to come a lot closer to neutralizing the matchup. Part of that is being physical, but not necessarily in the “hit the deck” sense. As Garnett noted yesterday, defense is more about being cohesive and understanding the game plan than it is about throwing running elbows and slamming Tyler Hansborough in the face.

“Everything can’t be so simple and so easy,” Garnett said. “You have to put some type of defensive impact into the game. When you’re playing a team on the road you try to make it as uncomfortable as you can. When you’re playing against two of the greatest to ever play the game, guys who are offensively gifted, high basketball IQs, know how to play the game and seen numerous traps, numerous schemes, you have to be cohesive. You have to be together. You have to understand the strategies, the plans. The margin for error is very small at that point. We’re a defensive team. We didn’t get into a defensive flow and slow down anything.”