The postponement also means no fight for the undefeated former British super-middleweight champion Joe Calzaghe, who was due to meet the Brazilian Luciano Torres on the same promotion.
Calzaghe's fellow countryman Robbie Regan, the WBO bantamweight champion, had already withdrawn from the card.
The fight has been called off again because Grigorian has a shoulder injury, although Ayers has been waiting more than a year for his second shot at the WBO crown. A previous date this year was scrapped when Grigorian first sustained shoulder trouble.
Ayers' first attempt at the title ended in a wide points defeat by Italy's Giovanni Parisi in Rome in April 1993.
Ayers said: "I just don't know what to say other than that I'm gutted. I was due to fly out tomorrow morning. It's unbelievable for it to happen at this stage. I'm No 1 contender and must fight for the title at some stage. Nobody can stop me from doing that.
"But the main point is there will be no fight on Saturday, which means all my really hard training has gone to waste. I was just down to making the weight, that's all there was to do. The graft and sparring had all been done. I don't know what will happen now. I am hoping to hear more within the next few days."
Herbie Hide insists money is not the motivation behind his campaign to win back the WBO heavyweight championship.
Hide took home pounds 2.6m for losing the same title to Riddick Bowe just over two years ago, and he has told his trainer, Jim McDonnell, that he would fight America's Tony Tucker at the Norwich Sports Village on 28 June for a zero purse.
"I want this fight so much that I would fight Tucker for nothing," Hide said. "I don't spend a lot of money on myself. I put it into my house, my needs are not great. The interest I earn on my investments in a month, I would not even spend in a year.
"But you don't know what's coming up in the future. I may get married and have kids, but at the moment I don't have to support a wife and family. I say that the only time in life when a person is financially secure is when they are dead."
Hide has invested pounds 20,000 of his fortune in importing three sparring partners from America - Linwood Jones, Kim Odum, and Ross Purrity - to help him prepare for the fight.