This is a common issue for adults (and kids!) with dyslexia. It can be particularly challenging when you have a word spelled correctly, but your usage is wrong.
Your question and the sensitivity you have are applauded. Yes, students with learning disabilities (current school term for dyslexia) may need special accommodations when playing sports.
Universal Design for Learning (UDL) is the conceptual framework that is used to design technology devices, software, and learning materials to give all students equal opportunities to learn.
You have done a good job laying the groundwork for success by helping your student organize his binder with dividers and pockets. Now we have to figure out how to get him to use it!