Less than 0.01% of people have what it takes to become professional athletes, and only a small proportion of these ever manage to make the cut. People with a passion for sports can still participate off the field, though:
Every team needs someone on the sidelines to talk with sponsors, plan transport and accommodation, do the accounts, manage training facilities, negotiate contracts, and so forth. Without these essential functions, the best players in the world will end up going exactly nowhere.
A sports management degree is rooted in business fundamentals. As such, they do qualify students for management careers in other fields. The focus, however, is on the sports industry. Universities offering sports management as a major often maintain close ties to local sports teams and clubs, both amateur and professional. This allows them to offer internships to deserving students, keeps them close to where the action is, and also helps them to show students how things are actually done in practice.
Especially at postgraduate level, there are several specializations available within the field of sports management: organizational leadership, project management, media relations, sports marketing, and so forth. In all cases, though, prospective students should be naturally outgoing, detail-orientated, and have a knack for solving problems. Naturally, detailed knowledge of a sport, including behind-the-scenes aspects like the politics and history of the various teams, is an advantage.