Daniel Jacobs (L) and Peter Quillin pose in front of the Brooklyn Bridge ahead of their Dec. 5 fight at Barclays Center. Photo by Ed Diller – DiBell Entertainment.

Danny Jacobs’ friendship with Peter Quillin has been an interesting subplot to their big 12-round middleweight fight on Dec. 5 at Barclays Center.

The two have forged a fatherly bond over their young sons and shared success as residents of Brooklyn.

But they sounded like anything but cronies as they kicked off a press conference on Wednesday with Quillin questioning Jacobs’ character and the normally even-tempered Jacobs, a cancer survivor, bristling at allegations he may have acted callous toward a fallen opponent.

“Well this isn’t the battle of characters,” Jacobs said defiantly to RingTV.com, “because my character speaks for itself.”

Following the news conference, it was pointed out to Quillin that he and Jacobs both saw their last opponents leave the ring on stretchers.

Quillin (32-0-1, 23 knockouts) brutalized Michael Zerafa with a fifth-round knockout while Jacobs stopped Sergio Mora in the second after he suffered a right ankle injury and couldn’t continue after getting knocked down.

Quillin said the biggest difference between their situations is that he stopped celebrating once he saw Zerafa was badly hurt while Jacobs (30-1, 27 knockouts) showed no remorse to Mora.

When he was asked who had the most impressive knockout, Quillin, 32, took a shot at Jacobs’ in-ring etiquette.

“Me, because I made sure that I cared about the guy going out on a stretcher,” Quillin said. “Danny celebrated, not even going to check on his opponent. This is still a sport. You want to show good sportsmanship – ‘You okay bro?’ Then celebrate your win. I couldn’t celebrate seeing a guy leave on a stretcher. I seen him roll his eyes behind his head. I care. So that’s the biggest difference in the fights.”

Quillin went on to describe the unspoken code of conduct he tries to abide by that he feels Jacobs, 28, violated.

“This is a sport and I don’t fight (with that angry) emotion,” he said. “I just fight with knowing there’s a certain principle you have to have with this sport.”

The normally unruffled Jacobs seemed taken aback by the comments.

Jacobs has emerged as a respected spokesman for cancer survivors and anti-bullying causes. He makes frequent appearances at hospitals and recently visited his old high school, Erasmus in Brooklyn, where he discussed bullying and other teenage ills.

In 2013, Jacobs launched his own foundation to deal with cancer awareness and combating bullying and obesity.

In short, Jacobs takes his position as a role-model seriously.

So he didn’t like having his character questioned – even if it was over an emotional reaction he had to an opponent he wasn’t particularly fond of.

“So the fact that (Mora) hurt his (ankle) – I could have been like, ‘How you doing?'” Jacobs said. “But he wasn’t the nicest guy in the world, Sergio Mora. He’s not a guy that I can say I like outside of the ring, so no, I don’t really care about too much about what’s going on with him. Did I show sportsmanship? Yes, I wished him well on Twitter after I seen he had a cast. Is this a battle of character? No, because my character speaks for itself.”

Quillin didn’t stop there, however. He also ridiculed Jacobs’ jawline, seemingly questioning his chin and his ability to take a punch. Jacobs was stopped in five rounds by Dmiry Pirog in his first title shot in 2010.

“I see he has a big-ass chin,” said Quillin, ranked third in THE RING’s middleweight ratings. “You ain’t seen his chin? That mutha(expletive) chin is huge. It’s pointing right there. I see it.”

Similarly, Jacobs took aim at Quillin’s lack of amateur experience and late start to the sport.

“I definitely see holes in his game,” said Jacobs, No. 6 by THE RING. “And I think he’s still sort of learning on the job. You can see holes in his defense. You can see holes in his offense as well.”

But even if the two don’t really like each other anymore, the two need each other professionally to disprove the perceptions that they have faced soft opposition (Jacobs) and made unsound business moves (Quillin).

From Milton Nunez (TKO 1) to Jarrod Fletcher (TKO 5) to Caleb Truax (TKO 12) to even Sergio Mora (TKO 2), Jacobs’ recent opponents have been underwhelming.

“That’s why I’m so grateful for this opportunity because I understand what this fight can do for me if I look impressive and get the victory,” Jacobs said. “It can make me an instant superstar. I’ll be able to gain the respect of the fans who’ve been criticizing me for a long time.”

Quillin’s last opponent, the unheralded Zerafa, was similarly mocked.

But it’s been his actions out of the ring that have raised eyebrows.

Quillin didn’t exactly endear himself to fans when he failed to make fight for his April 11 encounter with Andy Lee. The two fought to a tense draw.

He also puzzled fans when he vacated his middleweight belt last summer instead of facing his mandatory challenger, Matt Korobov, in what would have been a career-high purse of $1.4 million. Quillin explained away the bizarre decision by saying his wife had just had their first child and his uncle was sick with cancer and he wanted to be by his side.

“What can I say?” Quillin said. “Of course people when they sit back and watch people make a decision – but it’s not for everyone to understand and I understand that. You cannot make everyone happy.”

On Dec. 5, the two will be able to wash away some of that criticism.

Punchlines: Quillin said that if the two networks, HBO and Showtime, could work together to make Floyd Mayweather-Manny Pacquiao in May, then who’s to say he couldn’t one day meet Gennady Golovkin in a joint-network venture, given the large amounts of money to be made.

“Look how much money had to be in the pot for (Mayweather-Pacquiao) to happen,” Quillin said. “Mayweather just got $280 (million) for fighting Pacquiao. I’d be cool with five mill. I’m cool with ten (to face Golovkin).”