Gwen Stefani had to scrap a planned performance at a Las Vegas gala on Thursday night (27Apr17) after reportedly rupturing her eardrum.

The No Doubt frontwoman had been due to hit the stage at the annual Power of Love event at the MGM Grand Garden Arena, where retired tennis star Andre Agassi and business mogul Ronald Perelman were honored, but a medical emergency prompted Gwen to cancel the appearance.

According to the Las Vegas Review-Journal, Gwen's eardrum ruptured during a flight on Tuesday (25Apr17), and she had to seek treatment at Los Angeles' Cedars-Sinai Medical Center.

She was advised by doctors to rest while she recovered, and was therefore unable to fly to Las Vegas to sing at the Power of Love event.

Sources tell the Daily Mail guests were alerted to the change of plans by an announcer, before a video message from Gwen was played for the audience.

Apologizing for her absence, she said, "I am so sorry that I cannot attend tonight, but I wanted to send a message of congratulations to Andre Agassi and my dear friend Ronald Perelman."

Jennifer Hudson was drafted in as a replacement for Gwen, and the Dreamgirls star performed alongside fellow headliner Jon Bon Jovi to help raise funds for the Keep Memory Alive charity, which aims to find cures for brain disorders like Alzheimer's disease.

Stefani has yet to comment on her ailment on social media.

She is thought to have suffered the ruptured eardrum after appearing on Monday (24Apr17) and Tuesday's (25Apr17) live shows for talent show The Voice, on which she and her boyfriend, country star Blake Shelton, are mentors.