Mario Balotelli and Felipe Melo fired back at stinging criticism from Juventus and Italy defender Giorgio Chiellini.
Chiellini was scathing of his former team-mates – the Juve captain accusing Balotelli of being "a negative person", while adding the Italian forward deserved a slap during the 2013 Confederations Cup.
Brescia star Balotelli hit back at the comments made in Chiellini's new autobiography via social media on Saturday.
"At least I have the sincerity and courage to say things to your face," Balotelli wrote on Instagram, tagging Chiellini.
"Since 2013 you've had a lot of chances to act like a real man, but you haven't. Who knows what you'll say one day about your current team-mates.
"A strange captain... if this is what being a champion is then I'd prefer not to be one. I've never disrespected the Azzurri shirt."
Chiellini, 35, was more brutal when it came to assessing former Juve colleague Melo – the Brazilian midfielder who played for the Bianconeri from 2009 to 2011 before eventually joining Serie A rivals Inter.
"Even worse was Felipe Melo: the worst of the worst. There was always a fight with him. I also told the managers: he's a rotten apple," Chiellini wrote.
Melo – who now plays for Palmeiras – told Gazzetta dello Sport: "It would be interesting to know what incident he's referring to. I don't have a problem responding to him.
"I never disrespected anyone in Turin, but he says that Balotelli deserved a slap and that I was the worst of the worst and that there was always a threat of a fight because of me.
"He always pissed himself. I'm sorry, but it's easy to speak badly of others in a book.
"Perhaps he's still angry because when I went to Galatasaray we knocked them out of the Champions League and we beat Italy with Brazil.
"He's won nothing at international level and saying things like this shows him to be unprofessional.
"It shows a lack of respect and I won't say any more. Some things have to stay in the dressing room."