As mentioned above, you are entitled to be treated by a physician of your own selection.  It is important that you stick with a physician that will handle your case appropriately and not be at the whim of the Employer/Carrier.  DO NOT sign any forms which waive your right to or designate a physician as your choice of physician.  Occasionally, these forms are given to you by a port doctor at the time of a drug test.  Read any forms that the Employer/Carrier or physician gives you to sign.  If you have a doubt, do not sign it and consult an attorney.