The 36-year-old Briton, who has 28 wins from 31 bouts, ruptured an Achilles tendon in his defeat to underdog Tony Bellew in London in March.
The former WBA heavyweight champion, who was advised by doctors to retire after he underwent major shoulder surgery in 2013, has had long periods out of the ring without ever officially calling it a day.
"I am going to fight again before the end of the year," the Briton told reporters at a news conference to announce the first event to be put on by his new promotion company Hayemaker Ringstar.
