What is the average salary for a soccer player per year?

Depends on several different aspects. The club and league within which the player is and also it depends on their ability within their assigned role.

For example. Wayne Rooney gets paid an alleged £4.6 million because he is one of the best players in his role and plays for Manchester United in the Premiership. Man U are a club that has a lot of finance as does the Premiership.