Amateur sport photography lens for nikon d5100?

I'm looking for a lens with a fast f stop, 2.8 or faster, since it will mainly be used for taking photos of my friends playing footy on a friday night since i can't play any more with kidney issues. Any for not too much over $1000 would be nice since i'm 15 and not making that much money the tamron 70-200mm 2.8 has been the main lens i have been looking at, since the nikon equivalent is more expensive and doesn't auto focus on my d5100. Any help/ recommendations/ advice would be really appreciated!

A cap on the beginning of a sentence makes your text a load better readable.

Nikon's 70-200 f2.8 does autofocus on the D5100.

I've used the tamron before they added a motor and was less than impressed by it. It's really quite slow to focus in bad light. I found sigma's 70-200mm F2.8 EX DG APOMacro HSM II better for those kind of things. Not having OS would be a pity but you can partially overcome that by using a monopod.