This injury is a bear. I'm recovering from one myself. Did stupid stuff, including coming back from it WAY too soon. Here's a key: just because it feels all healed up doesn't mean the tissue actually IS all healed up. Based on a combination of professional and personal experience, here are a few things I'd do:
1. Go see the best physical therapist you can find and get evaluated. I resisted this but I finally relented, went to someone who is expensive and doesn't take insurance, but also looks at the body in a far more comprehensive way than the typical PT. We found that my gastroc complex as a whole was firing properly but that when the medial and lateral segments of my gastroc were asked to fire independently (by rotating the position of the leg and then doing certain movements), they were almost shut down. I'm an exercise therapist by trade (but not a PT), and she taught me a few very useful new exercises to incorporate into my rehab. You want to make sure all the muscles of your legs and hips are working properly so you don't place undo strain on any one of them. Tennis requires a lot of 'ballistic' movement, much different than just running in plane. We are all well served to ensure our bodies are working in as comprehensive a way as possible.
2. 'The Stick' is a great idea. I also found a very cool company that sells some amazing products for self-myofascial release work. check out www.tptherapy.com
. I ordered one of each of their products and I'm VERY impressed. I was using the smaller roller on my calf last night, especially on the soleus, and wow, it just does a much deeper, better job than I can do with a stick roller. and if you do foam rolling, get "The Grid". I already had 3 different foam rollers. Bought this one to try it out and I'm throwing the others away.
3. Use a combo of ice and heat to pump more blood through the injured area. That can help moderately accelerate healing and reduce scar tissue formation.
4. Stretch a lot, walk a lot, but do it to tolerance. Pain is a signal you're doing something your body isn't ready to do. Don't try to run until you can walk without ANY pain for at least 7-10 days. Try walking up steep hills before running, that's a nice test.
5. Once you start running, if you normally run where you contact the ground first with your forefoot (like the Pose technique), you may wish to consider temporarily going to heel strike. That will lessen the demand on the posterior chain of your leg. Then you can migrate back to a forefoot strike as your leg demonstrates it is ok with this demand.
6. Once you can do that ok, do some VERY light jogging backwards. Puts a very unique demand on the calf complex. Then once that's ok, I'd go out to a court and start 'running the lines'. Or you can do it in a park, or an empty side street. Do lateral shuffles, forward movements, backward movements, all that stuff. Make sure that all feels ok. Start REALLY slow and then ramp up. If those are ok, then go to sprints.
7. The zensah calf sleeves are a great idea. Use compression when you come back.
8. Static stretching has its place but not immediately before a match. Use charlie's advice on dynamic warmup. Once you start playing again, get to the court earlier than usual and go through a FULL dynamic warmup routine.
9. Engage in a leg strengthening program that doesn't just strengthen your calves, but strengthens ALL the muscles of your leg. When working your calves, make sure you are working both the gastroc AND the soleus. An exercise that works one does little for the other. Work on the hamstrings, work on the quads, the glutes, the hip flexors, ALL of it.
being out is a bummer but use this time to get your legs into the best shape the've been in for years and you'll come back better than ever. Good luck to you and keep us posted on your journey back.