I shoot a lot of high school soccer -- and the lights are usually pathetic -- if you hope to capture any usable images - anything that won't let you shoot at f2,8 won't work for you.
I'll repeat that - you need a lens that will let you shoot at f2.8.
Not only does it not let in enough light for good exposures, they focus so slowly you won't be able to follow the action.
If you have a pro body (I shoot a Nikon D3S) that allows to shoot at very, very high ISO levels you can shoot at f4 - barely.
I've been shooting my D3S using my Nikon 200-400 f4 and finally decided I needed more light so I've just ordered one of the new Sigma 120-300mm f2,8 Sport Zooms.
With respect to WB - the more the WB is off, the less happy you will be as the combination of under-exposed images + a poor WB will render most images unusable.
Shooting sports at night or inside a poorly lit gym is difficult and without fast lenses is damn near impossible.
One last thought - someone mentioned a 200mm f2 --- a great lens but a disaster for sports because the depth of field is much to shallow.
