WBO super middleweight champion Joe Calzaghe says Carl Froch must prove his credentials before challenging him.
"Froch will have to work like I have done to establish myself on the world scene," said Calzaghe.
After last week's win over Damon Hague, Froch said he was the best super middleweight in the world and would be ready to dethrone Calzaghe in a year.
Calzaghe has extended his contract with promoter Frank Warren, who wants the Welshman to meet Antonio Tarver.
"I'm currently in talks with Tarver's camp, and I'll also be making an offer to Glen Johnson," said Warren.
"I'm not at all surprised he [Johnson] beat Roy Jones Jr, as I've not been impressed with him at all in his last few fights.
"I'm delighted that Joe has followed in the footsteps of Danny Williams and signed a new deal with me.
"I believe he is one of the best pound-for-pound fighters in the world, and will go on to prove that in the next 12 months."
As Calzaghe prepares for the 15th defence of his super middleweight belt against Kabary Salem in Edinburgh on 22 October, he remains desperate for a title shot at light heavyweight.
WBC and WBA title-holder Tarver would be a great match-up, but the Welshman may not be a big enough name in the USA to secure the deal.
Calzaghe was due to meet IBF champion Johnson in the summer, but withdrew at short notice with a back injury.
The subsequent war of words has soured relations between the camps.
"Calzaghe disrespected me and spoke about me like I was the challenger and didn't have other options other than to go to [Britain]," Johnson told the Seconds Out website.
"But now I have knocked out Roy Jones. What does he think now? He's probably thankful he never fought me."
Johnson's manager Henry Foster remains even more enraged, saying:
"What has Joe ever done? Does he even leave his own front yard?
"Are you seriously telling me he'd have accepted a fight with either [Bernard] Hopkins or Jones if it wasn't 100% on his terms?"