The best of times for TNT tonight could turn into the worst of times tonight for ABC and the NBA if the wrong team wins.

With a huge rating looming for TNT off of an Indiana-Miami Game 7, it could be a ratings disaster if LeBron James and company are watching Pacers-San Antonio in the finals on ABC.

That nightmare scenario would feature two small market teams; Indy ranks 26 while San Antonio is 36. One of them, Indiana, has no marquee stars, while the other, the Spurs, has perhaps the most unheralded superstar in the history of sports. Sorry, but Tim Duncan doesn’t get people rushing to their TVs.

ESPN already got the short straw this year with the Western Conference Finals. San Antonio’s four-game sweep over Memphis (another small market team) only averaged a 3.4 rating.

Meanwhile, Game 5 of Pacers-Heat on TNT averaged 8.5 million viewers on Thursday. Still waiting for numbers for Game 6 on Saturday, but they definitely were high. Given the build-up, it seems likely TNT could pull in more than 10 million viewers tonight.

Those fans are tuning in to see if LeBron and Miami can avoid the upset. They will stay tuned in on ABC if the Heat win and go for a second straight title in the finals.

It’s all about star power, and with the possible exception of Tiger Woods, no star makes the ratings meter move more than LeBron James.

So they won’t be impartial in the ABC/ESPN executive offices tonight. And the NBA certainly doesn’t want to risk negative reading stories about low ratings for the finals.

Make no mistake, they will be rooting for the Heat tonight.