Frontman Alex Turner had to pull out of a gig due to illness recently.
Questions continue to be asked over whether Arctic Monkeys will make their headline Glastonbury set tonight. The band are due to play on the Pyramid stage in the prime slot on Friday night.
Last week, the band were forced to cancel a gig in Dublin as frontman Alex Turner was struck down with laryngitis, casting doubt on whether they'd make their performance tonight. If the band do make their gig, it will be the third time on the bill, having also appeared in 2008 and 2013.
Glastonbury organiser, Emily Eavis, told the BBC she had a back-up plan but was confident they would be there. "He's recovering, I'm sure we're going to be all right," she said.
"We've got a couple of back-up plans if not. We've always got back-up plans for everything", she added.
Speculation has been rife as to who will replace the Sheffield rockers should they have to pull out. Acts include The Churn-ups, who some suspect are none other than Dave Grohl's band Foo Fighters. It comes as the mystery band has no digital footprint and is widely anticipated as a huge guest.
There are also rumours that Harry Styles could step in. The 29-year-old pop singer performed at Cardiff's Principality Stadium on Wednesday and Thursday and is due on stage in Werchter, Belgium on Saturday.
Arctic Monkeys are also still scheduled to play their upcoming set in Glasgow two days later on June 25, with a gig planned at Bellahouston Park. The show will be the final stop of the ongoing UK tour.