just rest a lot i know it would suck but some of the tention would go away it helped with my back a few months ago.

How to Treat a Torn Tendon in a Shoulder. Instructions Apply an ice pack to the shoulder for 20 minutes at a time, every 2 hours. If you do not have ice packs, you can simply place ice cubes into a plastic bag. Place a washcloth or towel between your body and the ice pack so the cold is less intense. The ice will help keep swelling to a minimum. Take anti-inflammatory medicine such as ibuprofen or aspirin immediately after the injury occurs. Continue taking it until the tendon has healed. Do not exceed the recommended dose as listed on the medicine bottle or packet. This will help with pain and swelling. Let your shoulder rest as much as possible. Refrain from lifting heavy objects. Putting extra strain on a torn tendon will prolong the healing time. If you are experiencing intense pain, you should put your arm in a brace to reduce the stress placed on your shoulder. Arm braces are available at most pharmacies. Stretch the tendon gently until it is healed to ensure all mobility is returned to the shoulder. The tendon may become stiff and lose elasticity if it is not stretched during the healing process. Do not stretch to the point that it becomes painful as this could injure the tendon even more.

Thank you for answers. I've been told I need surgery to repair the tendon. Just wondered if it wise to play tennis til then. I've had a cortisone injection which freed shoulder up a bit.

I had what I believe was the same problem from a racket ball accident. It created a pretty big bulge just above my shoulder. A surgeon told me he could fix it but it is pretty major surgery and recovery would take quite a while. He also told me that the "fix" would last several years then probably break again. Because of that I opted out. That was several years ago and it's fine now.