This paper presents an application of information theory to identify sets of key players in social networks. First, we define two entropy measures that we use to analyze the structural properties of a social network. Then, we propose a new method aimed at finding a set of key players that solves the KPP-Neg and KPP-Pos problems. Our preliminary experimental results indicate that the entropy measures can be used effectively to identify a set of key players in a social network. Key words: Social Networks, Knowledge Discovery, Information Theory, Entropy, Centrality