Panthers coach Ron Rivera said he's ''not concerned'' about his job security following Carolina's latest fourth quarter collapse. The Panthers blew a 12-point lead in the fourth quarter against the Chicago Bears before losing 23-22 Sunday on a last-second field goal by Robbie Gould. It marked the fourth straight game Carolina (1-6) has lost after holding a lead in the fourth quarter. ''At the end of the day I'm being evaluated,'' Rivera said. ''But right now, it's not something I can be concerned with. If you start to worrying (about your job) and playing for the wrong reasons you're not going to give yourself a chance. When the moment comes or the time comes to be concerned, or not be concerned, then I'll go from there.'' Source: Associated Press