The announcement was made on the singer's Twitter account at 4.43pm that he was not well enough to perform.
The special gig will feature some of the biggest names in music.
The chart-topping star decided to move out of his London flat for a while during the pandemic.
The singer's mum is a primary school teacher and suggested he lend his music to Joe Wicks' PE lessons.
The 'Castle On The Hill' singer earned more than 'Harry Potter' star Daniel Radcliffe and Harry Style combined.
Ezra on how he got his injury: “It’s about as rock and roll as you’d expect from George Ezra."