Bono has revealed his frustration at cancelling last year's Glastonbury performance by releasing a video filmed in his hospital bed.
The singer - due to play the rescheduled show at the festival on Friday - was forced to pull out in 2010 with just a month to go after a back injury which involved surgery.
Now the Irish superstar has posted a short clip online showing him as he lay groggy in his bed in Munich, Germany, after the operation talking about his "disappointment" at pulling the show.
In it he says: "This is not very rock and roll. This is a different kind of rehab.
"They've explained to me that apparently I'm not indestructible. The drugs by the way are very good," he says in the film, on the band's website.
"U2's never played Glastonbury - I was really looking forward to it. I actually cannot believe this has happened. Really sad, disappointed, p***** off about that - this is, actually, Spinal Tap."
Last year the band were replaced with a hastily arranged performance by Gorillaz. However U2 guitarist The Edge did appear at the event when he made a guest appearance on the Pyramid Stage with Muse.
Meanwhile, campaigners have vowed to interrupt U2's set with a protest against the band's alleged "tax dodge".
Direct action group Art Uncut is plotting a "visual spectacular" during the Irish band's headline appearance on the Pyramid Stage. The protest is expected to involve a giant inflatable let off by the group. Placards will also be held up declaring "Bono tax dodger" and "Bono pay up".
Campaigner Charlie Dewar said: "U2's multimillion euro tax dodge is depriving the Irish people at a time when they desperately need income to offset the Irish government's savage austerity programme."