I believe concentration is a practiced skill that for the most part can be learned even when factors external to the game itself try to impede on a player's focus. I do believe there are both external and internal factors at work when considering influences to a player's concentration. For certain some external factors might include noise in practice or game environments, new surroundings, temperature, lighting, and what I call practice or court elements. For example in a small gym with little room on the sidelines, or a huge arena where teams must adjust to spatial perception that can cause problems with concentration and focus on the task at hand. In addition you have internal factors working as well.
Coaches can control to some extent external factors the the use of drills and time.
With each additional direction, pivot, or pass call change you are forcing your players to pay attention to the timing and execution of cutting, passing, and moving without the ball to make the drill work. This doesn't mean you shouldn't require total concentration in all drills or phases of a game. It does mean that you want to know early on if you need to push your team verbally or through actions to improve immediately their concentration level. Now pay attention here. I firmly believe that in the execution of every single drill in practice you can improve concentration by putting a time and rate of success goal on it.