C., I perceive that you are concerned that your son may have some form of ADHD, because you talk about medications. You mention special education class and say your son benefitted from some one on one time. Maybe you should look into getting an evaluation.
Diagnosing ADHD and other attention challenges is best left to psychologists who specialize in those fields. Although many school psychologists are very good, many are not at the PhD level. The tests that the school psychologists perform are more limited in scope because their focus is on school related tasks and also due to time constraints. A full work-up is performed in two half-day sessions, and is expensive, but may help you know your son. And, who knows, an outside phychologist may only want to talk to you and your son to decide if a work-up is even needed, and may be able to put those concerns to rest. You may find out that what your son does is in the normal range and some techniques to keep him focused.
He obviously is listening to things that interest him, though he appears easily distracted. Or, he may be only focusing on things that he considers important. Perhaps he is not as interested in the soccer as he is in other things, and is only there for the fun. That's OK as long as it is what you want out of it is a time for physical activity and don't care if he's not the next Pele.
There's a difference between an inability to focus and distractability. Maybe getting a professional to evaluate your son is a step to knowing what to do. And, I'd like to ask, what do you see as the problem with how your son approaches the world? He appears to get good grades in school, retains detailed information, and interacts well with others. He may not pay attention to things that he deems less important, so maybe it's his choice of priorities that you find a problem. My take is that his thoughts of Tranformers are normal for the age, boys in my days pretended to be cowboys all the time.
My sister's oldest son was a lot like your son, even more so. He forgot to hand in school work, and focused on Legos. He's a great person now, and though he has taken his time finding his own way, he is successful in his life. Each of us is different, it would not work if we were not so diverse. I hope your son is one of the dreamers who invent the next great helps to mankind because they are focused more on what could be and less on what is. We need them all.