As always, check
www.fredmiranda.com to get a good idea of lens quality.
If the games are during the day, an f4 (70-200) would be fine. Attach a 1.4x teleconverter to that and you have your 300 focal distance and then some.
I do shoot Canon, and the
L lens is as good as it gets. You might look into the 100-400 too if you really need the extra reach. All depends on where you're located. Feel free to ask me questions, as Canon lenses is an area I've studied for many years!
FYI- I use a 70-200f4 with 1.4x, a 400 5.6 prime, and a 17-50 2.8 Tamron.