Click image for larger version. 

Name:	MC_as_GK.jpg 
Views:	129 
Size:	94.2 KB 
ID:	970
Ok, at first blush, this looks ok. 4-3-2-1 should be good, right?
On further investigation, it turns out E. Silva is a MC playing keeper.
So, I'm thinking rule 1 is: a Goalkeeper playing Goalkeeper.