Former world heavyweight champion David Haye will announce on Tuesday he is to return to the ring after an absence of more than three years.
Haye, who has not fought since he stopped fellow Briton Dereck Chisora in 2012, is to hold a news conference at London's O2 Arena at which his next opponent will also be present.
The 35-year-old has been training with Shane McGuigan - son of former world champion Barry - and has indicated he wants to reclaim the world title he lost to Wladimir Klitschko in 2011.
Legendary former world heavyweight champion George Foreman believes Haye could be the only person who can take the belt from Ukrainian Klitschko.
Londoner Haye tweeted: "You sure know your stuff George Foreman and you'll be happy to know I'll be back to regain the heavyweight crown #HayemakerIsBack."
Klitschko, 39, is preparing to fight another Briton, Tyson Fury, in Germany on Saturday. He has not lost a fight since 2004.
Former two-weight world champion Haye - who has won 26 of his 28 bouts - says he has had offers to fight Liverpool cruiserweight Tony Bellew, Irishman Martin Rogan, American Malik Scott and Mark de Mori of Australia.
Is Haye's return a surprise?
Yes and no. Haye's original plan was to retire before his 31st birthday but he has already come out of retirement once - to fight Chisora at Upton Park in 2012.
Two proposed fights against Fury have since been cancelled because Haye needed reconstructive surgery on his shoulder, after which he was advised to retire.
There is, however, a sense of unfinished business. He won the world title in thrilling circumstances when he defeated Russia's Nikolay Valuev, despite giving away seven stone to his 7ft opponent.
He followed that with victories over John Ruiz and Audley Harrison to set up a fight against Klitschko - the dominant force in the division - but was easily beaten, blaming a toe injury for his subdued performance.
Haye looked back to his best in dismantling Chisora, but a succession of injuries have stalled any plans to try to reclaim the world title.
What kind of shape will Haye be in?
When in peak fitness, Haye poses a threat to the best in the division because of his ability to mix speedy footwork with some heavy punching.
Since stepping up from the cruiserweight division, he has faced a succession of taller and heavier men but has managed to fuse his extra speed with power.
That appears to be behind his decision to link up with Shane McGuigan, who has overseen Carl Frampton's rise to the world title in the super-bantamweight division.
"Looking at all the British and world fighters, the one fighter that stood out for me was Carl," said Haye.
"Carl's speed, timing, accuracy and punch variety is something that I didn't have in my arsenal. The guy behind that is Shane, so he was the guy I sought out."
Who could he fight?
Haye will have to prove he is still operating at world-title level when he returns, but he will be keeping a close eye on Saturday's fight between Klitschko and Fury.
He has been mocked by Fury after pulling out of two fights against his fellow Briton, and has spoken of his desire to put right his perceived wrongs against Klitschko.
A fight against Bellew should not be ruled out, while Haye is likely to also jump at the chance - should it present itself - of fighting unbeaten American Deontay Wilder, who holds the WBC belt.
Wilder, 30, is expected to fight again on 16 January in New York.
Could Haye be ready by then? It would be a risk, but one he might believe is worth taking.