Matthew Macklin has pulled out of his middleweight clash with Jorge Sebastien Heiland in Dublin due to his lead trainer Jamie Moore being shot twice in the legs in Marbella.
Macklin was looking to secure a fourth world title chance in what was billed as an official eliminator for the WBC crown at 160lbs.
However, the Irish favourite has postponed the bout, which would have taken place on 30 August at the National Stadium, after Moore's attack in Spain.
"I am disappointed to have to postpone my fight but in the light of the circumstances and the disruption to my preparation it is the right thing to do," said Macklin.
"Every fight at this stage in my career is of huge importance and being 100 per cent for the night is vital."
As a result of Macklin's withdrawal from the card, Matchroom has revealed the entire show has been scrapped until later in the year.
Macklin added: "We will make an announcement shortly on a new date and I look forward to fighting in Dublin in 2014."
Moore was reportedly shot at five times and hit twice, in the leg and hip over the weekend and is now in hospital.
He tweeted on Tuesday: "Thanks for all the well wishes. Overwhelmed. Gutted and confused about what happened, but thank God I'm ok. X'.
"It's at times like this that you realise how well your thought of. I've had unbelievable support. Means a lot it really does. #BoxingFamily".