I'll chime in (a few days late):
The most obvious problem is that your players were mostly "in shadow" meaning that the camera had to up the exposure level for the players in order to get them "properly exposed". The problem is that in that type of conditions that will as you've seen lead to a bright sky being overexposed.
The best "standard" approach to this is to position yourself to where as much light as possible is falling on the players and reflecting back to your camera.
For some scenes, flash can be very valuable, such as a good Canon SpeedLite.
Using one of these two approaches will enable you to lower your overall exposure, so that the sky will come through better.
And then, you do your best in post-processing. Good software will have tools that will brighten the shadows and also lower the highlights (the bright sky). You can find the best settings for a particular scene and "batch process" your shots of that scene.
But there is one additional bit of "advice" here:
If your shoot is important to you so that you want to get the "most" of your shots, then I'd suggest you shoot in the Raw format. This is because the Raw files have more data that covers a wider dynamic range, meaning that those bright skies have more detail to recover as do the shadows. Raw processors can do a lot with that data, not just "toning down" those bright skies but also enhancing the colors of what should be a nice blue sky. I've done a lot of outdoor shooting where at first glance the skies seem "impossible" but a quick run through my Raw processing software (Lightroom, or it could be Adobe Camera Raw or another capable app) has made a big difference.
That being said, there are some scenarios where sure, let it slide, it's the action that matters. But if the image matters as a whole, then, well, consider the bits of advice!