High School Football - Canon 7D / Lens-70-200 f/2.8

I have a Canon 7d with a Canon 70-200 f/2.8 lens - Non-IS.  I have been really frustrated shooting night time high school football games with this camera/lens.  I was on last year and get some great info, but my pics aren't as clear as my friends Nikon.  I'm ready to give up all my Canon equipment and move to Nikon.  I have an older Canon 20d w/ Tamron 70-200 f/2.8 which I don't use. I haves scoured the internet for custom function settings and have found a few good sites.  I am shooting AI Servo on Manual, usually shot with evaluative metering, but now trying Center-weighted, using single shot focus 2nd square from top middle (not sure if I should be selecting a highlight point or not) and use a monopod.  I was trying to stay at ISO 3200, but then I read it was okay to take it higher.  I only have 2 games left to shoot and would love some great shots.  I've tried expansion focus but someone said that might be too jumpy.  I have tracking sensitivity on -1.  I don't know what else to do - really frustrated!  Thanks for any help you can give.

D5000, Shutter 1/320, AV 3.2 - no listing for shutter

Nikon D7000, ISO 4600, Shutter 1/200, AV 5.0

From all the posts I've read, everyone says to keep it above 1/500 and usually shoot with AV 2.8.

Canon 7d, ISO 6400, Shutter 1/640, AV 2.8

Canon 7d - ISO 6400, Shutter 1/400, AV 2.8

Canon 7d w/ Canon Lens 70-200 f/2.8 Non-IS - ISO 5000, Shutter 1/500, AV 2.8