Paul Gallen has launched a withering verbal spray on fellow former NRL forwards Mark Carroll, labelling him a "two-faced coward."
The comments come after Carroll, a former New South Wales State of Origin representative, accused Gallen of backing Bronson Xerri.
Xerri's immediate future in the game is in doubt following a positive performance-enhancing drugs test last week. While not condemning Xerri's choices, Gallen questioned the Australian anti-doping authority's motives in announcing the test result two days before the start of the revamped season.
Carroll slammed Gallen, referencing the former Sharks skipper's own past issues with ASADA when he was caught up with Cronulaa's supplement scandal.
"I can't believe this kid [Xerri] did this and now Gallen wants to back him and say that it was okay," he told 2GB Drive.
"Are you cracking jokes? Mate, you don't take drugs. If you want to take drugs, you don't play our game.
"Gallen, he got slapped on the wrist for what he did, he got away with it, and this kid is going to have to pay the penalty."
Gallen fired back at 'Spudd', accusing the former Manly prop of talking behind his back.
"First of all, 'for what I did', we all know it was a club-run program where players were duped and doped," he told 2GB's Wide World of Sports Radio.
"I was one of 16 players to have pleaded guilty and I bet you that goose couldn't name another two or three players.
"I just love the big tough guy with the big mouth. I was with Mark Carroll probably three or four months ago doing a luncheon with him, he's shaking my hand, he's best mates in my face, nice as pie and (then) wants to get on radio and say things like that.
"If you don't like someone and you think someone's done the wrong thing, don't shake their hand and be nice to them, be a man about it and say, 'Mate, you've done the wrong thing, I don't like you'. I just think he's a two-faced coward.
"I have that many blokes who talk behind my back about what happened at Cronulla and have no idea about what actually happened, yet when I see them, they're nice to me.
"Then they want to get on radio and spruik themselves, all he's trying to do is create a headline and probably get a job because he's a dumb s**t."
Carroll has since replied, saying facts and history shows that Gallen is the "coward".
"It’s always got under my grill that Gal only missed a few games and a Kangaroo tour,: Carroll told Fox Sports.
“He was supposed to be the leader at Cronulla.
“That’s not leadership, that’s throwing young blokes under the bus.
“That’s the real definition of a coward.
“I was just an average footballer who trained hard to get the best out of my body.
“You don’t do drugs. You are taught as a kid. Period.”