I had a basketball player who had surgery on his ankle. What we did is as follow:
Go on the seated calves machine, add a moderate amount of weight on it
Reach the lowest position you can reach and hold it there. As fatigue sets in you wont be able to hold the weight as much and you will find yourself going down lower. Hold for as long as tolerable (it will burn like a mofo).. the goal is to do 3 total minutes under tension. A first you will need several sets o do this, but over time try to it in as little time as possible.
Do that at every single day. Ideally at the start and end of each workout.