Britain's Carl Froch has injured an elbow in training and been forced to abandon plans to fight Julio Cesar Chavez Jr in Las Vegas in March.
The WBA and IBF super-middleweight champion, 37, says he hopes to return to the ring in the summer.
"I'm disappointed to have to let this opportunity go but at this stage in my career I have to make every fight count," said Nottingham's Froch.
Froch last fought in May, when he stopped George Groves at Wembley.
"We have been deep in negotiations for some time and we were almost ready to go," said promoter Eddie Hearn.
"Carl has gone into fights before not 100% fit and paid the price and he has made the right decision to hang fire.
"We will have a meeting early next week and plan out 2015. I'm confident we will see him back in the ring this summer."
Froch plans to make a further announcement next week.
Froch sparked talk of retirement on Sunday, when he posted a photo of a pair of boxing gloves on social media.
Mexican Chavez, 28, is a former WBC middleweight champion and son of legendary fighter Julio Cesar Chavez.
Froch, nicknamed the Cobra, has lost just two of his 35 fights, with 24 of his 33 wins coming by way of knockout.