Tony Bellew and David Haye's rescheduled rematch will take place at London's O2 Arena on May 5.
The British heavyweight rivals had been due to meet on Dec. 17 but Haye was forced to pull out on Nov. 20 after suffering a torn left bicep in training.
The former world heavyweight and cruiserweight champion needed surgery to repair the injury, which he described as a "freak accident" while training on a flight of stairs.
"After my freak accident down a stairwell last month I was heartbroken not to give everyone the ending to 2017 I wanted," said Haye.
"Since then I had to accept the cards I had been dealt, remain positive and focus on factors which are within my control -- rehabilitation and rescheduling the fight.
Injury has also forced Haye (28-3, 26 KOs), 37, to postpone fights against Wladimir Klitschko, Tyson Fury (twice) and Manuel Charr.
The bicep setback was the latest in a series of injuries that have kept the Londoner out of action during his professional career. Since a wide points loss to Klitschko in a world heavyweight title unification fight in 2011, Haye has fought just four times.
And he has already recovered from one serious injury earlier this year after needing surgery on a ruptured right Achilles in the 11th round loss to Bellew on March 4.
"Over the past five years, I've had a number of challenges to overcome, but learnt often during times of adversity we learn and grow," said Haye.
"As a result, come May 5th, Tony will be faced with a more experienced and more determined opponent.
"In 2018 the Hayemaker will be back and I will once again give fans the biggest, most explosive, blockbuster fight nights they deserve."
Bellew (29-2-1, 19 KOs), 34, who broke his hand in the second or third round against Haye, also wants to fight former WBA-WBO-IBF world heavyweight champion Fury, who has not fought since November 2015, in 2018.
After winning the WBC world cruiserweight title in May last year, the Liverpool boxer stepped up a division to tackle Haye and upset the odds with victory.
"I was looking forward to a great victory in December and a relaxing family break over Christmas but my mind is still very much on this fight and I will punish him for that," said Bellew.
"I now have a very clear plan for 2018 and that is to knock out David Haye and then knock out Tyson 'Stavros Flatley' Fury and end both their careers but first things first I need to rid the sport of David Haye on May 5 and I look forward to doing this in what I believe will be an explosive fight."
Apart from any fight featuring WBA-IBF world heavyweight titleholder and ESPN's No 1 in the division Anthony Joshua, a Bellew-Haye rematch is expected to be the biggest fight in the U.K. next year.