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Everyone above is right on target.
1st - shoot another game but adjust exposure, use Av apreture priority mode or manual
- the 85 set at 1.8 has razor thin DOF, set it to 2.8, at 3200 ISO and you should get a bit fatter DOF to work with and a few more keepers.
2nd - If you are shooting multi-shot, not single shot mode, AF in dim light could be an issue
- the 7D has a more accurate option rich AF, 8 FPS and cleaner ISO 3200, 18 vs 10 MPs with a little bit more noise, but it will allow you to crop if needed. I'd rent one before buying tho, plus I'd wait on any 7D purchase. It's a 3yr old body and it's due for and upgrade...
3rd - The 135L is a killer sharp lens at f2, AF is really fast, but DOF is again razor thin.
- Stop it down a bit and DOF gets better, it will also get you a bit more reach.
I'd try stopping down your 85 to f2 or f2.8, shooting another event, maybe a practice session, before buying anything. You mentioned motion blur, this is more then often a technique issue. It takes time to anticipate the action and capture a keeper. Your best option is practice, practice, practice...anywhere, anytime...shoot daytime and indoor pickup games, and don't limit your subject matter, shoot everything you can.
I've a 40D and the 85, practice with it...a ton...you will get more keepers in time.
Good luck with your choice and enjoy shooting, your journey...
The video below probably won't help a ton, but take a look. It's a well known web shooter with a huge Fro...that goes back to his 1st indoor Basket Ball shoot with his 1st film camera. He usually shoots with a Nikon D4, it proves to be quite the challenge, but points out that the gear isn't always the issue, the shooter's eye, ability to anticipate is the key. You just have to get out and shoot more...
Photographing Like I was 13 again - 5 Min Portrait with FILM