Hi, OP!
Below is a link to an album (first link) with 14 shots from my 5DMIII, 100-400L MkI on a ball-head monopod. It's soccer and I think faster than football. I've worked with the 70-200 and shorter lenses, but only the 100-400 will do on the football field. When the action is near you, the 100mm fl is what you need. When it moves to the opposite end of the field, you need a 400mm fl. The MkI lens, The Pump, zooms very quickly and easily. The 5DMIII focusses very quickly with it, and I'd suspect the 6D would do so also. With that kit, I shoot 1/500s, f/5.6, and ISO whatever but for this set it ranged from 10,000 to 16,000.
Personally I'd recommend shooting some games to really get a feel for the action. Yes, you must anticipate the action. You have to get into the rhythm of the game and become a part of it. I'm a techie, emotions and feeling not required, but "feeling" makes a big difference in connecting with the action. You still may want to connect with the CL post, but try some fast action sports as you can. I take 600 to 1,000 shots at a game. Only so many count. If you're doing it to get faces of most or all of the team members, more is definitely better. I've added a second link to all of my photo albums; the soccer and basketball photo albums are obvious, for what it's worth.
Good luck!
http://grahamglover.zenfolio.com/p380696282
http://grahamglover.zenfolio.com/f593136965
EDIT:
Let me add one more link, found below. Here's your story. While only 52 images, it tells something of the progression of the game, and includes images that aren't always "action" shots but still a part of the event, the story. Make it interesting for the viewer and you'll do fine. Again, good luck!
http://grahamglover.zenfolio.com/p75870197