Actually, if you're on a soccer field, and the kids are far enough away, there's a good chance they're focused at infinity anyways, so you may not even need to

Actually, if you're on a soccer field, and the kids are far enough away, there's a good chance they're focused at infinity anyways, so you may not even need to focus (although your camera should be set to MF) as long as you've got the aperture small enough to give you wiggle room on the DOF.