Justin Timberlake canceled another concert on his "The Forget Tomorrow World Tour" after he suffered a back injury in New Orleans.On Saturday, the 43-year-old singer announced that his show at the Paycom Center in Oklahoma City would not take place on Dec. 2 as previously scheduled. "I’m so sorry Oklahoma City," the "Selfish" hitmaker wrote in a message he shared on his Instagram Story. "I have to cancel the show on 12/2. I hurt my back in Nola and my doctors have instructed me to rest a little bit longer. Thank you for your support — y’all know I hate doing