Yeah I found that the players' eyes were mostly useless but often times the composition of the photo is helpful. For example, if players are gathered on the right edge of the frame and there's a bunch of blank space to the left, the ball is likely over in the open area

I used where the fans were looking instead. It worked sometimes.

I assume the players look where they are going, and at other people instead of the ball (since they can predict the trajectory they probably look where it will interact with something, not where it is.).