by Rihanna is struggling with some form of illness and was unable to perform at a planned concert Monday night.
According to Live Nation, the "Pour It Up" singer was forced to cancel a show in Houston "as a result of illness," but plans to return to the stage in Dallas Tuesday.
The canceled date in Houston is her third cancellation in just over a month. As widely reported, Rihanna cited illness when canceling shows in Baltimore and Boston.
Fans that purchased tickets for the Houston date are being asked to retain the tickets for use at a later date, which will be announced at a later time.
Rihanna is touring in support of her seventh studio album, "Unapologetic."
