Anterior Cruciate Ligament (ACL) tears are severe and relatively common injuries with potential long-term consequences. Rehabilitation is a vital part of recovery, but patients frequently have trouble adhering to their Home Rehabilitation Programme (HEP) long-term. There are several reasons for this, (e.g. pain, boredom, having no expectations, etc). This paper aims to present a first step towards a Virtual Reality (VR) application that can improve adherence to the HEP. An analysis of themes is undertaken to identify why patients have difficulties in continuing their HEP, and based on this, a storyboard for a VR application is created with the forward lunges exercise as a case study. After the storyboard, a mid-fidelity prototype is designed and tested by one participant to obtain feedback and improve the prototype in a future second iteration. The participant’s responses show potential for improvements of the prototype in terms of presenting the game and the environment for a better experience. The use of Meta Horizon Worlds as a prototyping tool allows for faster iteration without the complications of developing a high-fidelity VR application. The importance of discussing barriers with patients, storyboarding and prototyping is highlighted and discussed, showing that they are important steps to create a VR application that will be used to improve a monotonous exercise.