Ataris have been forced to cancel their Sonisphere show after one of the band members contracted suspected swine flu.
Dirty Little Rabbits will also miss the debut of the rock festival with drummer Shawn Crahan suffering from illness and fatigue.
Speaking about pulling their appearance, Crahan said: “Nothing is worse than canceling shows and we hate to do it, but after weeks of going all over the world and playing some of the biggest shows of my career, and now being in the home stretch on completing the Dirty Little Rabbits debut album, I’m just mentally and physically drained.
“When you finally you hear it, you will all understand. First impressions are so important. If I don’t feel we’re giving everyone 100%, then it’s not our art. I promise you that the Rabbits will be there one day and it will be worth the wait.”
Despite the setbacks, organisers have confirmed that the build is a day and a half ahead of schedule with festival chief Stuart Galbraith also telling Virtual Festivals that there will be some very special guests performing on the Sunday at 2.45pm.
When asked if the guests could be Machine Head, who previously pulled their appearance at the event, but will still be on-site at Knebworth, Galbraith smiled and replied cryptically: “It would be unfair to raise fans’ expectations but at the same I’m not prepared to deny it. I should have said no comment!
It is ABBA tribute band Bjorn Again that bosses believe will be the big surprise act of the event though, with the group set to wear specially modified rock costumes and including Metallica covers in their set. “The sight of 45,000 Metallica fans singing to ‘Dancing Queen’ will be something to behold,” Galbraith mused.
Although his company Kilimajaro Live is no longer involved in the event, Galbraith also confirmed that people who had bought tickets to Big Green Gathering, cancelled earlier in the week, will be able to enter Sonisphere this weekend.
The main acts start on Saturday, but festival-goers arriving early tomorrow are set to kick off the weekend with a ‘space and aliens’ fancy dress party. Galbraith admitted he’s dressing up as Flash Gordon's nemesis Ming The Merciless.
Organisers also revealed that Sonisphere Finland has been the most successful festival in the series so far with a sell-out 60,000 crowd making it the biggest rock event ever to take place in the country. Bosses said they are looking to increase the capacity there to 75,000 in 2010 with Poland, Greece and the Czech Republic other possible destinations for the event to take place.
Tickets for the event are still available; standard weekend camping tickets are priced at £157.50, while weekend tickets are £132.50. Day tickets are available for £67.50.
Click here to buy Sonisphere tickets.