By Daniel Chavkin Carolina fired head coach Matt Rhule on Monday, creating the first coaching vacancy of the season. The Panthers fired Matt Rhule on Monday to create the first head coach opening of the year, and the rumors are already starting. The biggest potential name on the head coach market might be former Saints coach Sean Payton, and Panthers owner David Tepper could try to make a splash and hire the former Super Bowl champion. However, it will not be easy to simply hire Payton. According to NFL Network’s Ian Rapoport, the Saints still own the rights to Payton since he technically reti…