How could I use an image of a pro athlete?

I would like to know the legalities of using an image of a pro athlete on a t-shirt for sale? I figure that it would be illegal to use somebody elses photographic work. But what about a sketch, ink work or some other rendering that was done through me or an artist that was working for me. I don't want to take any risks and have the MLB, NBA and NFL after me for not doing my homework.