Employee thinks supervisor is out to get him
After recently presenting a written warning to an employee for performance issues, he told me that he felt the working environment was very difficult to work in, that is boss and trainer are condescending and have made fun of him, and he thinks that they are out to get him fired. I asked him to elaborate and send me his grievance in writing with specific examples of his concerns. He is not sure he wants to have it investigated. Where do I go from here? I have vague remarks with no specific examples and the employee not wanting me to speak with the supervisor.