Dr. Warner is Associate Professor in the Department of Anesthesiology at the Mayo Clinic.
He serves as the Director of the Mayo Clinic Patient Blood Management program. He also serves on the Patient Blood Management Committee of the American Society of Anesthesiologists and Secretary for the Society for the Advancement of Patient Blood Management.

He is the past chair of the Research Committee of the Society of Critical Care Anesthesiologists.

Dr. Warner is highly active in clinical and translational research in the space of anemia, transfusion, and patient blood management, supported by the National Institutes of Health.