TV stations can shoot from anywhere, since they basically own the games, and they choose to put their camera just above the last seat on the main floor, where I was for this shoot. But, here is what my sideline, or near sideline shots look like. http://optimagroup.smugmug.com/Vanguard-Football-9192014/i-vLpGDMK
For these I did not use the 2x tele III
The only TV cameras up that high are used as part of a multi-camera setup that includes numerous cameras on the field level as well. The still photographers and other video stringers are all on the field level, too. TV and newspaper photogs shooting high school and college football games all universally shoot from the sideline, I know because I did it for years.
First thing, get on the ground. Even the first row of the stands is too high. Second, get as close to the sideline as you can. You need to eliminate all the sidelined players, coaches, cheerleaders, etc. from your action shots. Trust Robert Capa's advice, "If your photographs aren't good enough, you're not close enough." Third, you need to be in front of the line of scrimmage, so that the play is coming AT you. All of your sideline action shots, you are behind the line of scrimmage, meaning that all we can see is backs. And move ahead when the line of scrimmage moves.
Everything that everybody else has posted in this thread is correct, constructive criticism. Try these tips and you'll save yourself a lot of money!