Is your concern that his grades are likely to suffer, or that he's not really learning ... or something else?
My son will be in his shoes next fall. I don't know exactly how it will go, but in deciding on the school, part of what helped my son was the school's focus on academics. They do send tutors on the road, for example.
So my expectation is that baseball will consume much more of his time, but that he will also learn, and -- assuming he applies himself -- get good grades.