Employee ran over a pot hole while driving a Getman, causing lower back pain. This was on 9/11/09. Did not report it until 9/12/09 which was his last day of rotation.He was off for 4 days, returned to work on his next shift. 9/17/09. while at work on 9/17/09, he complained of lower back pain,went to our medic on site & then sent down for evaluation by a doctor.