I don't think he is saying that it is some big secret. He probably did not show enough in practice to warrant more playing time.
When you are only riding 7 horses, and some of those are a little needy, why would you think much of anything was shown or not shown in practice? I certainly saw enough positive in the limited minutes he got on the floor to merit more time. Unless he simply dogs it daily, and that doesn't appear to be his playing style, I don't think his practice skills were the issue.