The coronavirus disease 2019 (COVID-19) pandemic has necessitated adoption of telerehabilitation in services where face-to-face consultations were previously standard. We aimed to understand barriers to implementing a telerehabilitation clinical service and design a behavior support strategy for clinicians to implement telerehabilitation. A hybrid implementation study design included pre- and post-intervention questionnaires, identification of key barriers to implementation using the theoretical domains framework, and development of a targeted intervention. Thirty-one clinicians completed baseline questionnaires identifying key barriers to the implementation of telerehabilitation. Barriers were associated with behavior domains of knowledge, environment, social influences, and beliefs. A 6-week brief intervention focused on remote clinician support, and education was well received but achieved little change in perceived barriers to implementation. The brief intervention to support implementation of telerehabilitation during COVID-19 achieved clinical practice change, but barriers remain. Longer follow-up may determine the sustainability of a brief implementation strategy, but needs to consider pandemic-related stressors.