I really do not recommend getting a expensive wide aperture lens with a body that has no AFMA. Narrow apertures usually hide focus inaccuracies in the depth of field, but its tough to hide front or back focus at f/2.8 or wider. You can, of course use it at f/8, but I doubt if you want that.
The images appear to be back focused, were you using AI Servo? Is the lens focusing accurately with a static object? If accurate on a static object at f/2.8, then its either a issue with not using AI Servo, or not having the AF point on the eye or wherever you want the focus point to be.
You may need to send the lens and body to Canon to be calibrated, with the 60D, there is no other way when lens and body do not match.
Well, the 50D had microadjust... you can blame Canon for stripping that away. I do have a second 70-200mm f/2.8L that I was going to sell so if this is back focused, then I might have better luck with the other. I generally don't like testing my lenses with a ruler and lined paper, but I think that might be worth it to see which lens matches my 60D better.
I didn't really get "lucky" at this game with the action coming towards me, so a ton of the shots are at a greater distance and the depth of field obviously wouldn't be quite as narrow if the subjects were closer.
Unfortunately, the subject of these action shots are less than enthralling... but my question is still about the lens quality and no so much the quality of composition or the shot.