It happened to my non dominant leg, and it took a year for complete recovery. My rehab started the day after surgery by balling my foot into a fist from reps, simply to keep the foot strong, and massage, stim. Three weeks of this led to picking up a towel with my foot, balling up the towel with my foot, and gentle isometric contractions of both the gastroc and soleus muscle. So for the gastroc, I contracted while standing for ten reps, three sets. For the soleus, I did them sitting, same rep scheme, same set scheme. I did this for about four to six weeks. After that, I began walking on a treadmill, then gradually doing physio ball quarter and half squats for ten reps, four sets. The ball keeps you neutral, not allowing the tendon to stretch too far. To recover ice packs for ten minutes, the hot soaks for twenty. I was able to bike two weeks after that program set in, then began walking stairs, stairclimber with a minimal range of motion. 5 months in, I began to do weighted exercises light, but with a bit of confidence. I began to be able to do light ten minute runs after six months. A year in, I was able to skip rope the doing footwork drills on court, without swelling or pain, also being able to do sprints full court. I had no problem getting my spring back due to it not being my dominant leg, but I had to be extra careful upon landing. That took a minute to get back, getting over the fear of it happening again.
Sitting around waiting for it to get better so I can put this together and get to work. 
