This is the question that people tend to ask each other, rather than asking a therapist.
In a nutshell - Sports Massage doesn't HAVE to hurt. Therapists don't set out to cause you pain, the tenderness may come as we locate the problem or the muscle which is holding the tension.
Firstly, the muscle is 'warmed up' using effleurage and petrissage techniques, then as the therapist works deeper, they may use different parts of their hands or their elbows to work harder into the muscle. The aim of the massage is to help you to release muscle tension which then allows you to improve your posture and flexibility.
Irritable 'knots' in the muscle may cause shooting or referred pain and these trigger points can cause weakness. The technique which is often used in this case is the application of pressure to the point. THIS is what can be painful as part of your Sports Massage.
The overall aim of a Sports Massage is dependent on the needs of the client. There are so many benefits that are not only physical; but physiological, neurological and psychological that are closely related.
A Sports Massage needs to be effective for YOU as an individual. The therapist should tailor the treatments to suit you. If you have no injury, but want to have regular massages as part of your training plan to keep the muscles strong and supple, then your massage shouldn't be painful.
The stretching of the soft tissue, the release of muscle tension, the reduction in pain and swelling, the improvement in muscle tone are all only the physical benefits.
So, if you are unsure, let your therapist know. Talk to them before, during and after.
Enjoy the process.