You don't need a canon lens, you don't even need a canon mount lens(although they'll be the only ones that'll easily autofocus).
You know aperture right? f/1.4 is a faster lens than f/2, lets in more light.
Exclusively daylight? you might not need 2.8 then, and if you're taking mainly photos you could find the 24-105 a good lens, f/4, a suitable focal length for you, fast autofocus(or so I've heard(usm)), also has an image stabilizer which would be nice for handheld shots when you're not shooting fast sports.