If a confined space will not be entered, then there is no need for rescue training for that space. However, if the confined space could be entered for any reason, such as in an emergency, then the requirement for rescue training at 1910.146 would apply before entry.
If an employer elects not to provide annual rescue training, the employer assumes the duty to prevent any incident which might require an emergency entry. If this is not possible, then rescue training must be given.