George Groves mocked Chris Eubank Jr’s use of social media and warned that his relationship with his father is at a "pivotal point".
Groves' WBA super-middleweight title will be on the line when he fights Eubank Jr in the World Boxing Super Series semi-final in Manchester on February 17.
"Junior is terrific at a soundbite, it's made him Insta-famous and it works for him," Groves said at a press conference on Tuesday.
"But I'm sorry to say that Junior isn't good enough, he doesn't have the pedigree or the ability.
"You're Insta-famous. Fantastic short clips on the bag or pads. They look great. You punch from the ankles from the get go.
"Junior's been craving the big fights without actually wanting them. He attaches his name to big fights and then they fall through and he boxes at a much lower level."
Groves then turned his attention to Chris Eubank Sr, who was present alongside his son, and drew a passionate response.
"This is a pivotal point in his relationship with his father," Groves said about Eubank Jr. "Up until now his dad has alleviated a lot of the pressure.
"So far the father has done him a massive favour by being desperate for the attention, talking about himself.
"But now people have bought into the hype and think he's legit. Now he's got to prove it. Has he outgrown the father?"
Eubank Sr responded: "That's hurtful, it is hurtful! Pedigree? Oh my goodness. I wasn't going to talk! Look at the ease with which [Eubank Jr] dispatched Arthur Abraham."
Pointing at his son, Eubank Sr said: "This is pedigree."
Eubank Jr added: "This my biggest fight in terms of profile and hype. At the end of the day I rise to the occasion and the bigger the fight the better I perform.
"I'm a man of my word - George, you will not see the 12th round. George is on a downward curve but this is my time.
"I'm a completely different guy to two years ago, a year ago, whereas George is the same guy.
"I know what's happened in sparring with George. I've felt what he has as a fighter and as a man. I know his weaknesses and strengths.
"Nothing he has can outweigh the fire and heat that's going to be brought down upon him."