Yes!
I agree with this. I don’t think OP said specifically what type of job their D is targeting, but sports management is often seen as a not quantitatively rigorous major. So getting those quant skills whether thru a different major or major/minor combo makes sense. Sports management majors will be competing for many of the sports management type desirable jobs with people who majored in math, finance, stats, data science, etc. I also agree that getting career oriented internships is so important in this area and requires a high degree of networking and self-motivation.