No law school in the country offers this degree. When you go to law school you, along with every one of your fellow graduates, earn a Juris Doctorate, or for short JD. You have to have a bachelors degree (4 year college degree) to apply to law school, in any major you choose. Once in law school you do not select a major like college, some schools have concentrations but definitely not in sports law, and the vast majority of law students skip concentrations all together because they are not that valuable in terms of employment. To specialize in an area of law most lawyers went to law school, go their JD and then worked in that area for a while to gain expertise, you don't get that kind of expertise in law school.
Edit: I don't know of a law school that is specialized in sports law, and you will probably have a hard time finding one that does. Most law schools that have a particular focus wouldn't focus on an area as small as sports law. Furthermore, sports law is really just a sub set of other larger areas of law, particularly Contracts, employment law, and agency law. So while you may find a law school specializing in Contract law, or employment law, because those are large areas of law that encompass concepts in sports law you will be hard pressed to find a school specialized in this specific area.
