A systematic review in 2002* examined this very question, and the results were a little surprising. Stretching does not seem to protect athletes/sports participants from injury.
Most coaches and trainers have now modified how they instruct people to warm up as a result of these findings. It appears to be more beneficial to warm-up than to stretch.
What does a warm-up involve?
It should be sport-specific, so for tennis you could warm up by jogging a few laps of the court, side-stepping and running forward and backward at a moderate intensity, all things which are done during a game. Your arms could be warmed up by swinging your racquet forehand, backhand, and serving a few times without the ball at first, then at moderate intensity with the ball. You could also hit easy volleys at the net, then gradually move back and hit harder.
Should you give up on stretching all together?
I like stretching. It gives me information on how my body is feeling on a particular day, and maybe that feedback can be beneficial to my performance. The key is to make sure you are warm before you do any stretching, and if you stretch before you play, it probably shouldn’t be sustained and end-range. Leave that for after the game when everything is very warm. You are more likely to create length in a warm muscle than a cold one anyway.
• Effects of stretching before and after exercising on muscle soreness and risk of injury: systematic review. BMJ 2002;325:468