Sensible application of clinical reasoning (CR) by the physical therapist is essential to achieving optimal patient outcomes. As such, it is important for institutions granting certification in orthopaedic manual physical therapy (OMPT) to ensure that the assessment of CR is adequately robust. At present, the dearth of validated instruments to assess CR in OMPT presents a significant difficulty in certifying institutions. Moreover, the lack of documentation of the development process for instruments that measure CR pose additional challenges. The objective of this study is to evaluate the sensibility of a newly developed instrument for assessing written responses to a test of CR in OMPT; a ‘pilot’ phase that examines instrument feasibility and acceptability. Using a sequential mixed-methods approach, Canadian OMPT examiners were recruited to first review and use the instrument. Participants completed a sensibility questionnaire followed by semi-structured interviews, the latter of which were used to elaborate on questionnaire responses regarding practicability and acceptability. Eleven examiners completed the questionnaire and interviews. Questionnaire results met previously established sensibility criteria, while interview data revealed participants’ (dis)comfort with exerting their own judgment and with the rating scale. Quantitative and qualitative data provided valuable insight regarding content validity and issues related to efficiency in assessing CR competence; all of which will ultimately inform further psychometric testing. While results suggest that the new instrument for assessing clinical reasoning in the Canadian certification context is sensible, future research should examine how rater judgment can be utilized effectively and the mental workload related to appraising clinical reasoning.