Kell Brook has warned Amir Khan that he has made a "big mistake" by inserting a catchweight of 149lbs into the contract for their grudge match.
The Sheffield Star will look to finally settle his rivalry with his long-term foe in Manchester this weekend after the pair finally agreed a bout.
Brook has admitted previously he struggles to make the welterweight limit of 147lbs which raised question marks over whether he would be at his best in their illustrious meeting.
But the 35-year-old has now claimed Khan delayed contract negotiations for "seven months" but he has removed any weight issues with hard work in training camp.
"He has made a big mistake by having me on for seven months with the contract," Brook said. "Unfortunately for him I have been training in that time, that is why I am smiling now.
"I am there with the weight, I could have made the weight three of four week ago. I am very comfortable with where I am at, the 19th is right there now.
"I am genuinely happy I am not putting a poker face on, I am just enjoying it all now as I have put the hard work in being away from my family over Christmas.
"It will be all worth it on Saturday night when I have my hand raised high. I truly believe that I will end this fight by knockout. I don't go out and hit stupid, but I believe if I am 100 per cent which I am that the shot will come off."
Brook is considered his best at around 154lbs and has previously explained his difficulty making the drastic cut against the likes of Errol Spence and Terence Crawford.
He has been away working in a warm-weather training camp in Fuerteventura during the festive period after reuniting with former trainer Dominic Ingle.
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The fighters will be forced to pay a six-figure financial penalty if they weigh in over the recognised 149lb limit ahead of fight night.
Former cruiserweight champion Johnny Nelson has encouraged Brook to pay the fine if weight becomes an issue to "double bluff" his rival.
"That is what they have got to go for," Nelson said to Sky Sports. "I believe that is what they are going to go for.
"But speaking about this weight issue, if it is tight pay the fine. They have to pay the fine because it is one or the other, I know what I think he is weighing and if it will make the difference pay the fine.
"If you come in a couple of pounds over the fight is going to go on because he would have double bluffed him. If you are going to squeeze me down for this I will come in over the weight and pay the fine."
