Nathan Cleverly's challenge for the WBO light-heavyweight title has been called off after champion Juergen Braehmer suffered an eye injury in training.
Braehmer, 32, was due to face Cleverly, 24, at London's 02 Arena on Saturday, but a cut eye suffered in training on 8 May has failed to heal.
The German won the WBO belt in 2009 and has made one defence but could now be stripped of his title.
If so, Cleverly - the interim champion - will be awarded the title by default.
Cleverly, who won the interim title in December after beating Nadjib Mohammedi on points, is unbeaten in 21 fights and was disappointed to see the fight called off.
"I'm majorly disappointed," Cleverly told BBC Sport.
"I had the call this morning saying Braehmer had not turned up at the airport.
"I was really disappointed but I'm not really that surprised. I had a feeling he would do this and I don't think it was a fight he really wanted.
"I made myself mandatory challenger so he had to fight me but basically he didn't want to fight me. He had no option other than to not turn up. He is going to be stripped of his title and I am going to be fighting for the belt.
"I'm just going to have to re-focus and get on with business now. I believe I will be fighting for the world title on Saturday now and that is motivation in itself.
"Ideally I would have liked to have beaten Braehmer, which I'm sure I would have done. This is the guy I wanted for ages, and I've been preparing for him for months. But what can you do? He hasn't turned up and he will be stripped.
"As long as I become world champion I'll still have the same amount of satisfaction.
"It's not easy to prepare for a change of opponent. I've been preparing for Braehmer who is a southpaw but this is boxing and this is what happens.
"I've got to make sure I'm motivated and re-focused on the fight.
"It's not an ideal situation but I'll get on with business, clear my head and be ready to fight and win on Saturday."
The 02 Arena card will still go ahead, with the joint headline fight between British super-middleweight champion James DeGale and fierce rival George Groves the bigger draw anyway. It is still hoped that unbeaten Welshman Cleverly will fight on Saturday but his opponent is unknown.
Any fight for Cleverly on Saturday could be the first defence of his title with his promoter Frank Warren saying he expects the Welshman to be awarded the WBO belt.
Braehmer last fought in April 2010 and has 29 knockouts from 36 wins with two defeats.
Since that last fight the 32-year-old was involved in a long-running court case that could have seen him jailed for 16 months for assault and insulting behaviour.
But Braehmer was cleared this year following an appeal meaning the German kept his WBO title.
His stock is already low due having only defended his belt once since winning it in 2009 while also pulling out of a January unification fight with Beibut Shumenov.
Cleverly's father and trainer Vince led the calls for Braehmer to be stripped of his title but maintained the Cefn Forest fighter would still be well prepared for any fight on Saturday.
"We will offer no excuses and Nathan will be ready to fight," he added.