Emp was cleaning around tailpiece when he felt a pull in his lower back.Employee finished shift.Emp continued to work until 5/18/12 and took 5 days vacation time through 5/25/12 during which time he scheduled an MRI. His 1st date of missed work was 5/29/12 awaiting results of MRI. We received notice of a positive MRI on 6/14/12. Employee remains off work at this time.