Star Players are the heroes of Blood Bowl, well-skilled veterans who became true living legends because of their long career in the arenas. Star Players are hardened mercenaries that will only offer their services to teams that can afford them. Their fees might be astronomical, especially since they will only play one game with you, but they know a lot of different techniques that could become real assets on the field. In fact, Star Players can turn the tide of a game all by themselves.
However, if their loyalty is for sale, they do have a minimum of ethics. Therefore, they will only play with members of their own race, and sometimes with their allies. For example, the famous Star Player Grashnak Blackhoof will only accept Chaos teams' offers while Blood Bowl legend Griff Oberwald will turn down any non-Human teams' offers.