Hydration, means of. Whether it's a canteen or a CamelPak, it makes a huge difference during the summer.
Depending on your playing style, kneepads. If you find yourself dropping to one knee on a regular basis, it'll protect you from kneeling on a wrong rock in the wrong place.
A cup is not unreasonable. It's an ugly scene, watching someone who just took one to the dangly bits.
And finally, fill in your profile with your location. Please and thank you.
"The Bird of Hermes is My Name, Eating My Wings to Make Me Tame."