Eto'o 108 GRL RW Aqua vs Inferno problem

I got all the players with their respective GRL on spot to trade them including the 106 GRL Eto'o too. When I try to put the 106 GRL - LW - Eto'o, the game DO NOT recognize that player (it is the first one on top of all the other players already set up) and won't let me complete that task to get Eto'o 108 GRL - RW. 

Can you solve this issue? Or is there something wrong with the trade...