Speaking to the Sun newspaper in the UK the singer said "I am worried about Susan Boyle."
"If she sells more records than us. She is a force of nature, that woman."
"I am anxious to see how our album does now it's out in the UK. I usually don't think about it but the day before I start to think too much," Followill added.
The Kings of Leon star was speaking in advance of the groups new album “Come Around Sundown” which is due to be released on October 19th in the US, a few weeks ahead of Boyle’s album launch for “The Gift” in early November.