ある・あります means "there is a." The only living things that work with ある・あります in this way are plants.
Your example sentence is saying "Also, he is a soccer player too." である・であります is a copula a lot like だ・です, but with different usage, usually formal speech or writing. If one being is two things, we need to use でもあります.
Nicole is Japanese and American (i.e.: she is a dual citizen): ニコールはアメリカ人でも、日本人でもあります。