Although most sciatica is from compression of the sciatic nerve at the spinal column, tennis players are also susceptible to the "piriformis syndrome".
The following exercises can help prevent a recurrence:
Suzanna McGee, who often posts here as sxftlion, also recommends doing self myofscial release to relieve the pain:
Sciatica or Piriformis Syndrome Treatment with Myofascial Release
http://www.tennisfitnesslove.com/20...s-syndrome-treatment-with-myofascial-release/
"Sciatica pain can be close to paralyzing—a numb, tingling or burning sensation going down in the back of your leg, calf and sole of your foot. The pain comes and goes unpredictably and playing tennis becomes impossible. However, you actually could have a tight and overused piriformis muscle, which is very common among tennis players. Luckily, it is also easy to correct.
Piriformis is the largest of the six muscles in the hip that are responsible for external rotation of the leg. If you have your leg planted, the piriformis turns the body in the opposite direction, a movement that tennis players do repeatedly thousands of times. An overused and tight piriformis muscle causes a lot of misery and pain in your sacrum, glutes and hips. It will twist your sacrum a little bit, causing a short-leg syndrome that adds to the problem. It can also compress the sciatic nerve and as a result, you feel the “sciatica” pain.
Quick directional changes in tennis impose a high risk on your piriformis’ well-being, especially if you are not well conditioned. Therefore, it is important to work on strengthening your glutes and hips, accompanied by regular stretching. Prolonged inactivity or sitting puts the piriformis muscles in trouble. If you sit at work or school most of your day and then start sprinting around the tennis courts, you may be creating future problems. An overused, shortened and sometimes even inflamed piriformis muscle contains painful trigger points. To remain pain-free, you need to stretch the piriformis to its original length and eliminate the trigger points with myofascial release.
Sit down on the floor, bend your legs and place your left foot on the top of your right knee. Place a foam ball under your left glute and tilt a little bit to the left, toward the outside. Roll around slowly until you find a surprisingly tender trigger point. Stay on it and wiggle around a little bit while breathing deeply, until the pain goes away. Keep rolling the entire area to find and eliminate all the trigger points. A regular myofascial re-lease will be less painful over time and your “sciatica” problems will be gone almost immediately. For more intense sensation or to reach the deepest, stubborn trigger points, use a tennis or lacrosse ball."