Anthony Joshua will fight Robert Helenius at the O2 Arena on August 12 after he was drafted in as a short-notice replacement.
Joshua was originally due to box rival Dillian Whyte in a rematch of their 2015 bout, but that was cancelled after Whyte returned "adverse analytical findings" in a random Voluntary Anti-Doping Association (VADA) drugs test.
Joshua's promoter Eddie Hearn was then tasked with finding a replacement fighter so the show could go on and have settled on Helenius. The Nordic Nightmare has a 32-4 record and only fought last weekend. It was Helenius' first bout since being knocked out by Deontay Wilder in the first round back in October and he stopped Mika Mielonen inside three rounds.
"This wasn't in the script," Joshua said. "I respect Helenius and may I say, I respect any male or female who steps into the ring. I am laser focused on the win. I can make steps forward to bigger and better things but the road map has a check point, Saturday night. May the best man win."
Helenius, meanwhile, vowed to "make the most" of his opportunity against AJ, stating: "I am excited about fighting Anthony Joshua on August 12. I am a true Viking that is willing to face any challenge at a moment’s notice. This is not an opportunity I was going to let slip away. I plan to make the most of it!"
Anthony Joshua advised to "play the game" by heavyweight boxing legendAmerican Gerald Washington was also considered as a potential replacement for Whyte, with his trainer Malik Scott saying the 41-year-old "would love" to fight Joshua. However, his scheduled fight against Derek Chisora on the undercard will instead go ahead as planned, with Hearn claiming Helenius will be a "tricky and dangerous fight" for Joshua.
"To get the news on Saturday was really disappointing, not only for us but for Anthony Joshua and for the fans," the Matchroom chief said. "But we got to work and we have done what we’re good at – and we have managed to keep the show on.
"AJ has been unbelievable throughout this whole process. He is someone who is ready to fight having trained for 12 weeks in Dallas with Derrick James. He has always been a great pro but this just shows me again the hunger he has for the sport.
"He wants to go out there this Saturday in front of a sold-out crowd at The O2 and perform. There were a lot of options. But we had to make sure it was the right fight for the right deal. I think Robert Helenius is a good fight.
"Yes, he lost to Deontay Wilder but that was by a shot that would have probably knocked out a horse! But he came to fight. He can really punch, he’s 6ft 8in and he won at the weekend. Ultimately there is criticism in whatever you do, but I actually think this is a tricky and dangerous fight."
Whyte, meanwhile, has insisted he is "completely innocent" and "can confirm without a shadow of doubt that I have not taken the reported substance". In a statement, he said: "I am shocked and devastated to learn of a report by VADA of adverse findings relating to me.
"I only learned of it this morning and am still reacting to it. I have also just seen that the fight is being cancelled without having any chance to demonstrate my innocence before the decision was taken.
"I can confirm without a shadow of doubt that I have not taken the reported substance, in this camp or at any point in my life. I am completely innocent and ask to be given the time to go through the process of proving this without anybody jumping to conclusions or a trial by media.
"I insisted on 24/7 VADA testing for this fight, as I have done voluntarily and at my own expense for all of my fights for many, many years. This is not the first time that I have been reported as having an adverse finding for a substance which I have not taken, and as I did last time I will again prove that I am completely innocent."