Thanks! At the moment I'm only focusing on soccer because that's what I know best : ) However, I can easily see this being extended to other team sports.

The main bottleneck is obtaining data around the teams that a player played for. Right now I'm depending on wikipedia because the soccer data is very rich and easy to parse. I'm not sure this is the case for other sports. The data could always be crowdsourced if there aren't any good data sources for other sports.