I would approach this in two ways: both on a personal level and enhancing job productivity. First, what is happening in the personal life? Is this person experiencing any crisis or sense of "is that all there is" within the framework of personal life? Encourage this employee to seek out what it is they have an interest in or have been wanting to do. This new-found inspiration and creativity, if activated, could cross over into the professional career. Secondly, professional team-building, mentoring and have employee involved with a training course within the company, or for the department could help the stagnation problem within the person and help the company produce a more focused and motivated worker. This will help instill confidence and pride back into the worker, and only helps to further service the company's overall outcome rate in a positive and advantageous way.
