Stretching is so important.
You will notice gains in your vertical and speed just by stretching before a match. PNF stretching is very good for this but involves more risk given you aren't in full control.

The pros won't find it a hassle to do. It will be second nature to them. I do it before all my games and training sessions, even if i'm just going to shoot a few shots with no real intensity. Do it before and after you will feel much better for it.