Esports is rapidly growing around the globe. The need for coaching best practice is becoming essential with growing investments in teams and players. In this paper, we investigated the current coaching practices and challenges in League of Legends professional teams by interviewing professional coaches from international teams. Our results showed unanimous agreement that coaching in Esports remains in its early stages, with a need to develop standards for coaching. We were able to understand the role of coaches, their different positions, and their skill requirements. We were also able to learn the challenges players face such as long practice hours, player attitudes, mental stress, and other health concerns such as back and wrist injuries. From the interview, we identified nine aspects of research requiring future studies.