Perry and Richie will be in the U.K. to perform at the coronation concert.
Morissette will be pulling double duty as she will also be a mentor to the remaining Idol hopefuls, who will be performing her songs live on stage. The contestants will also perform duets of Sheeran's popular songs.
Both are also slated to perform. Morissette will take the stage to perform one of her classics while Sheeran, who will be celebrating the release of his latest album, - (pronounced Subtract), will perform his new single. (He released "Boat" on April 21.)
Perry and Richie are taking part in King Charles' coronation activities in the U.K. as they've been tapped to perform at the coronation concert taking place Sunday. While they will be absent from Sunday's Idol, they will be beaming in live from Windsor Castle.
ET's Cassie DiLaura spoke with Bryan ahead of his set at Stagecoach Music Festival in Indio, California, on Saturday, where he hinted that the fill-ins for Perry and Richie are "big time."
"It's big time. It's big time," Bryan said. "The people that we have filling in, contestants have used their songs many, many times. A lot more than mine!"
American Idol airs live coast to coast on Sunday, May 7 at 8 p.m. ET/5 p.m. PT on ABC.