data validation with condition

I would like to create a cool line up sheet/player position list.

I have a data range named "Field1". In this range of cells I have validation boxes laid out in field positions.

1 cell below each validation box is the initials of the field position. (This could work for any field lay out...baseball,basketball court,football.etc..)

In column B is where the players first name is located and is the validation boxes list. Range name "FirstN"

What I would like to do is when I use the drop down list and pick a name, the position goes in Column E on the same row as the persons name in column C and at the same time strike through the name in column C to identify the player has been placed in a position.