There has to be something else. Something else that he is afraid of. Or maybe he's just not that passionate about football. I've heard kids say that as well. In my opinion, it's either that football isn't their passion, or that they are afraid of not being as good as they think they are going to be. They'd rather talk about how good they are, instead of going out and showing how good they are. I don't know the kid you are speaking of, so I'm not judging him personally. It's just what I've personally observed from kids who say that.
The kids I respect the most are the kids who play for Caston. They go out and get whipped every Friday night. Then they have to deal with the critics telling them how bad they are. But they continue to fight every week. When it comes to the game of life, those kids will be the winners.