Taking Back Sunday drummer MARK O'CONNELL has been forced to quit Linkin Park's Projekt Revolution tour after suffering a herniated disc in his back. The rocker underwent Magnetic Resonance Imaging (MRI) earlier this week (beg30Jul07) and has been advised to return home for treatment until further notice. Former Matchbook Romance drummer Aaron Stern, who has toured with Taking Back Sunday in the past, will replace O'Connell while he is undergoing treatment and recovering. In a statement, the injured rocker says, "I'm really sorry. I feel like I'm letting people down. I'm hoping to feel better and be back as soon as possible."