The trouble intensified in the third and fourth rounds and the end result was another disappointing performance which can scarcely make an impression on Stateside, though victory over Australia's mandatory contender came by way of a huge points margin.
Now the Newbridge southpaw must await the result of an X-ray to be cleared - or otherwise - for his proposed Atlantic City date at the Taj Mahal complex. Calzaghe said: "I've learned my lesson. I'll see a specialist and get things sorted out. It's just bad luck. In 27 fights I've only injured the hand against Robin Reid and Thornberry. I had zero rounds of sparring, nothing, but I was fit."
He sparred only 14 rounds for the fight with Reid, again looked ordinary seems not to have moved on since beating Chris Eubank to win the title 20 months ago. The scales, too, must be a weight on Calzaghe's mind. He is big for a super-middle and a move up to light-heavy is on his agenda within the next year. He added: "The weight is a struggle but I'm champion in the division, and there's some unfinished business to do. I want to unify the title, but in the next 12 months I'll be ready to step up."
Before Reid, Calzaghe underwent a wrist operation, and is paying a price for being a powerful puncher. Thornberry, while never a danger, stuck to his job. He was cut over the right eye in the first round, went down briefly in the second and lost 120-107, 119-109 and 119-108.
Warren added: "Joe's got a fighting heart, a good chin and can do the business. He doesn't make the weight easily, but he does it and he's a stayer. If we can get the hand sorted out, the future for him is bright."