— In the NBA, litmus paper is green.
At least that's the way it has seemed these past few weeks, as opponents try to measure themselves against the Celtics.
Just over a week ago, the Lakers failed on their home court, a humbling setback that raised the clamor about a potential trade. (The Lakers did make amends with a win in Boston on Thursday.)
Last week, the Mavericks passed their test on the parquet, with a riveting comeback.
Sunday, the Magic failed to a degree that Stan Van Gundy began to question his team's worthiness as a legitimate contender.
And now, this Sunday, comes perhaps the ultimate test, in terms of playoff implications, when the Heat arrive at TD Garden for the first time since the season opener.
At 0-2 against the Celtics in the four-game season series, the Heat need this one more than the Lakers, Mavericks or even Magic did.
Boston is not an immediate concern for the Lakers. Phil Jackson's team has a far more impending concern in south Texas. Ditto for the Mavericks.
And while Orlando did not look good Sunday, it at least has its Christmas Day victory over the Celtics to fall back on.
But the Heat have none of that, just a five-game elimination at the hands of the Celtics in last season's opening playoff round, a series that was expected to be far more competitive, considering the Heat entered as the No. 5 seed to the Celtics' No. 4.
No, lose Sunday and it would make the fourth and final meeting of the season, on the season's final Sunday, essentially moot. By then, Boston could be sitting its older players, which, essentially is the entire roster.
It is why, in a league in which coaches and players refuse to look ahead, or at least refuse to acknowledge looking ahead, the Heat did just that in the wake of their Super Bowl Sunday matinee against the Clippers, a full week before Heat-Celtics.
"I think we have big-picture and small-picture goals," said LeBron James, with the Heat's schedule lately littered mostly with small-picture games, save for the recent Thursday victory in Orlando. "You can't help but to look at the big picture. There are games that mean a lot.
"That game next Sunday could mean a lot."
LeBron, of course, has his own personal misery to exorcise on the parquet in advance of the playoffs, considering the way he either quit (the view of the detractors) or merely came up short (LeBron's view) in last season's Eastern Conference semifinals with the Cavaliers.
Even coach Erik Spoelstra acknowledges this as more than one of 82.
"We can make a push and get some momentum going into the break," he said. "It's not the most important thing right now. We're not obsessed with the other teams in the standings."
And yet, as he mapped out this week, including the intervening games against the Pacers and Pistons, he colored his case in, well, green.
"What I told the guys," Spoelstra said, "is we might as well as put ourselves in position next Sunday to pass them."
For the most part, the Heat's season, even with the addition of James and Chris Bosh, has been a no-passing zone. The Heat have led the Celtics for all of two days this season, actually closer to 36 hours based on the timing of the teams' schedules in early January.
As for the Celtics, statements have been their story of the season.
A year ago, Boston was riding along on cruise control, leaving serious doubts about the ability to make it to another NBA Finals.
This season, it might not even take until the All-Star break to come up with a Finals answer.
Because they're only getting stronger, save for the occasional slipup like Monday in Charlotte.
Kendrick Perkins is back now. Delonte West is expected back after the All-Star break. All the current time off will only have Shaq fresher for the postseason.
"What concerns me, is that we haven't been able to establish our bench," is Doc Rivers' current lament.
There would be a more sympathetic view on that count if Big Baby wasn't playing like the Sixth Man Award favorite.
"Not even close," Magic coach Stan Van Gundy muttered about where his team stands in relation to the Celtics. "Not even in the same ballpark as these guys."
For the Heat, the key is not to exit Sunday amid similar muttering.
Because then the mind games only figure to get worse. The following weekend, Dwyane Wade, James and Bosh will have to share the same locker room as Pierce, Allen, Garnett and Rondo as Eastern Conference teammates, with Doc Rivers as their coach.
With a loss this Sunday, it could prove to be an extremely chilly weekend for the Heat's All-Stars at Staples Center next Sunday.
Because head games long have been a key component of this Celtics' mix.
In last season's playoffs, the Heat's Quentin Richardson found himself in the middle of an ugly series-opening scuffle with Pierce and Garnett. This past weekend, Richardson, now with the Magic, experienced the same vibe.
"That's what they're great at," he said. "Despite everything, they're able to do their little things, do their antics. They play their game. They wear it out."
Is it possible for an opponent to be psychologically eliminated before the All-Star break?
The Heat, if not careful, could become Example A Sunday.
Or else it merely could be the start of an intriguing road to the Eastern Conference finals, with the Heat possibly to go into the All-Star break with the upper hand in the standings.
With a Heat victory Sunday, the hotspot of All-Star Weekend well could be the Eastern Conference locker room, a head game of four-on-three with very real long-term stakes. For the Heat, the right to talk back must be earned Sunday.