Long-term illness and injury leave vs medical leave (Human Rights Act)

Hi, I work for the Indian Band and I have a question related to one of our staff member, who is not on benefits but he was on a medical leave. Band was paying when he was away form work due to his medical illness but band now decided not to pay him any more unless he brings a doctor’s note stating he is fit to work and if there is any limitations or if needs to be accommodated or not. My question is, because he is diabetic and he lost his one leg and hand, and other hands finger are almost start falling down. He wanted to get back to work but i asked him for a doctor’s note with all the limitations and what kinda of accommodation we can provide but he came up with a clinical doctor’s note stating “(This patient wants to return to work. He cannot do any physical activities but can do supervision. There is no contra-indication for that sort of activity)”. But honestly speaking, this person is a Manager and his role requires more then supervision. What would you recommend in this Scenario? We are federally regulated and based in Alberta.