The 72-year-old "Love Hangover" hitmaker was expected to perform at the event this year but had to pull out and has already been signed up for a performance next year at the music extravaganza in Somerset, reported Contactmusic.
"Next year it's Diana Ross. I don't know where I'm going to fit," said Barry Gibb when asked whether he would be filling the Legend slot at next year's event.
"The people there were very kind to me and suggested a show perhaps next year. I would love to return to Glastonbury. But if it's not next year, it will be the year after, as I'll be on the road anyway," he added.
"I have no advice for her, just go there and have a good time. She's amazing, we were chatting just a few days ago.