The impact of an NBA championship on LeBron James cannot be understated, according to Hall of Famer and ABC analyst Magic Johnson, who predicts James will become an even better player.

“I think everything changes,” Johnson said off the air Thursday morning. “He can now feel, ‘You know what? I’m the best player in the world because I’ve won a ring. The ring says so, not the media, not the marketing says so. But my game actually says so.’

“We’re judged by championships. And LeBron will be bigger across the world with a championship. I think all the naysayers go away and I think it’s only going to make him better, too. Michael Jordan got better after his first championship, and I think the same thing happens for LeBron. His popularity will grow. The NBA benefits from that. … It’s going to be LeBron-mania like we’ve never seen before.”

Johnson added, “Thank God he’s in the NBA, that we have a chance to see him every day. And thank God he’s going to play in the Olympics, and that the world will get the chance to see this unbelievable dominant player on the biggest stage.”

Johnson said Kevin Durant deserves “a lot of praise for making LeBron even better, because a lot of times your rival or the guy you go up against will bring the best out of you. Larry Bird definitely did that for me.”

Jersey sales

James finished third in international jersey sales this season behind the Los Angeles Lakers’ Kobe Bryant and the Chicago Bulls’ Derrick Rose, the NBA announced Thursday. James was third in Europe and China, and second behind Bryant in Latin America.

PREGAME TALK

• James, who suffered from cramps in Game 4, said Thursday morning that he felt “good” and “I plan to stay hydrated.”

Chris Bosh cracked, “I gave him a six-pack of Gatorade and salt tablets.”

• James said he felt no anxiety Thursday morning.

“It’s always been a dream of mine even when I first picked up a basketball and started getting into the history of the game, how great it would be to hold that trophy up some day and be part of a championship team,” he said nine hours before the game. “I’m in position where I can be part of history.”

•  Dwyane Wade said he woke up tired Thursday. “No sleep. That’s what the Finals bring.”

He summoned Chicago-based trainer Tim Grover to South Florida this week because “everybody that knows my body — I decided to have them here and get me as much of an edge as possible.”

Wade has dealt with leg and knee issues during the postseason.

• Parent company Fox denied a Forbes report that the Heat is on the verge of signing the NBA’s second-richest TV deal, one that would increase Sun Sports’ annual rights fee from $80 million to $100 million, more than four times the value of the current deal that runs through 2014-15. The story “is completely inaccurate; no truth to it whatsoever,” Fox said in a statement.