I agree with Allie and luke's comment.
A concern regarding Allie's comment, is whether using the 504 may actually hurt his situation regarding his being able to stay in basketball.
And, adding to luke's comment, I have a brother, and sister, who were both involved in the high school athletics, and some of their grades slipped, meaning they had to put more time into studying to keep up with the rest of the class. Which brings to another point, keeping up with other kids in school should be done acedemically, as well as physically. Whether Social Studies are usefull in the future, or not, it is a general subject everyone should be familiar with.
An additional thought is whether the teacher happens to 'have it out for him', or if there are other students in the class that the teacher is just as strict about? Just thought that omitting that idea would help in deciding whether or not to use the 'CF Card'. Personally, I worked twice as hard in studies, and everything for that matter, in order to stay with everyone in school, and did not use any mention of CF along the way. I don't even think anyone knew I had CF, much less what it was, even after I graduated!
Edited: Ok, the only time I used the 'CF Card' was in order to use the 'Faculty Bathroom' in order to avoid ridicule by using the students bathroom,which, by the way, had all the doors removed, (because they all went to the john to smoke, anyway...hey, I avoided that nasty situation, as well!), so I had no privacy during those 'bad stomach days'.