Rapper Drake has pulled out of his headline appearances at this weekend's Wireless Festival.
The Canadian star, 27, was set to perform at the festivals in London and Birmingham.
But he told fans in a statement that he was too unwell to take to the stage.
It said: "To my beloved fans, it truly breaks my heart that I won't be able to perform as planned at Wireless... this weekend.
"I got sick a few days ago and although I am on my way to bouncing back, my doctors have made it clear that I am not physically fit to fly or deliver the performance my fans expect and deserve from me.
"I will be focused on resting for a quick recovery. I have the best fans in the world and I can't wait to come back to make more incredible memories together."
Festival organisers Live Nation said that Kanye West will now perform a second headline show at Wireless London and Rudimental will play an extended set in Birmingham.
Rudimental will be joined by "very special guests", who are yet to be announced.
Pharrell Williams, Tinie Tempah, Bruno Mars, Ellie Goulding and Robin Thicke are also on the bill.
The festival, celebrating its 10th anniversary, takes place in Finsbury Park in London and Perry Park in Birmingham.