D7000 AF Selection Question

Looking for a little advice on the AF setting I should be using for sports. I took some shots today at a soccer game and while the subject was in focus for some of them, I also got a lot where the camera seemed to lock on the background and not the player I was hoping to get. I had the AF set on AF-C and a 9 point grid. The attach photo is an example of where the background is in focus but the player is not.