He spent two years banging on the door of WBO super-middleweight champ Joe Calzaghe, who never invited him in.

As the WBO’s No. 1 contender for 25 months, Freeman “The Natural” Barr (27-4, 14 KOs) should have been welcomed inside to cut a deal, sign the papers and shake some hands.

But the big-money fight with Calzaghe never happened, and Barr finally lost his ranking and maybe a little of the dream, moving on with his career, wondering why the door to a world title shot with Calzaghe was never opened.

But the career that held so much promise in the 1990’s, started to fade in late 2001.

“The last time Freeman was 100 percent for a fight was when he fought Roni Martinez (in July 2001),” said Barr’s manager and trainer, Steve Canton of Fort Myers, FL. “After that fight, something was missing. He was having problems with his stamina, and that had never been a problem for him. He had a pain in his lungs when he did his roadwork.”

It took a long time to find the culprit, but they finally nailed it. According to Canton, Barr had sarcoidosis, a slow-moving disease that usually starts in the lungs.

“We thought he had allergies,” Canton said.

With the disease finally identified, arrested and treated, Barr is back in the fight game and looking for a second chance.

His first fight in 27 months was July 29 when he stopped journeyman Terry Acker (19-10-2) in three rounds in a fight in Fort Myers.

“That brought his confidence back up,” Canton said. “He looked real strong.”

Now Barr is looking for a bigger fight. He’d like a shot at Roy Jones Jr., but nothing’s happened yet.

“I think it would be a good fight for both Freeman and Roy,” Canton said. “If Roy is looking for another so-called tune-up fight after his win over [Prince Badi] Ajami, why not Freeman?”

According to Canton, Barr went to Sarasota to spar with Jones when Jones was preparing for his fight with Reggie Johnson back in June 1999.

“But they never sparred,” Canton said. “Roy saw Freeman working out and declared him to be a great prospect. He said he didn’t want to spar with Freeman because he thought they might end up fighting each other somewhere down the road.”

Barr is ready.

“I admire Roy and respect him,” he said. “But I think he’s lost a little. He’s not the fighter he was a few years ago. I think you can go right after Roy now.”

Barr has spent some time sparring with Glen Johnson, and that makes him hunger for a shot at Jones.

“Roy has been a role model for me,” Barr said. “And fighting him would give me a chance to see what I‘m made of and what he‘s made of.”

Against Acker, Barr fought at 171 and showed some of the old moves and strength that made him a top contender.

“He’s a rejuvenated guy,” said boxing announcer Bob Alexander, who has watched Barr from the beginning of his career. “He was the same Freeman Barr we’d seen all those years. He was in great shape and his punches were crisp again.”

Alexander remembers Barr’s last fight before Acker, a decision win over Tony Brooks over two years ago.

“He looked sluggish against Brooks, not like himself,” Alexander said. “I just figured he didn’t have much anymore. But against Acker, he looked like a totally different guy. But Acker is no world beater by any means.”

Barr won’t dazzle you with his speed or impress you with his power. But he does everything well.

“He’s a technician,” Alexander said. “And in all those years, he should have gotten a title fight.”

Canton drove the point home.

“Roy Jones used to be the best light-heavyweight in the world,” Canton said. “Now, I feel like he’s only the fourth best light-heavy in the state of Florida behind Antonio Tarver, Glen Johnson and Freeman Barr.”

See if Jones opens the door.