You can, it is done with an .edt file. I believe
this is the guide Canesdude is referring to.
@ Canesdude - the folder you place the .edt file in depends on what patch you are running. So if you are using 11.3 then it will go:
Steam
C:\Program Files\Steam\steamapps\common\football manager 2011\data\updates\update-1130\db\1130\edt
Non Steam
C:\Program Files\Sports Interactive\Football Manager 2011\data\updates\update-1130\db\1130\edt
You will probably have to start a new game for the file to become active though.