Last year the position with the most equal salary were goal keepers and the most unequal were forwards. This season goal keepers are still the most equal, but now midfielders are the most unequal. Here is the Gini coefficients for this season using MLSPU's data.
|Pos||Base Salary||Guaranteed Comp.|
As you can see midfielder are twice as unequal as goal keepers. Defenders are close to goal keepers and forwards are close to midfielders for the league as a whole.
Prior posts on 2015 MLS Income Inequality:
MLS Team Income Inequality
MLS Overall Income Inequality