How can you substitute players when someone is sent off??

[bakconhighway]

Hello, I am new to FM2014, so this is probably a dumb question but i couldn't find the answer anywhere...
How can you substite positions when someone is sent off, without changing tactics (I dont want to mess with the tactics because I am using one that was created by someone else)?
Say for example, I am playing 3-4-3 and my Defense gets sent off. it becomes 2-4-3, but I want it to be 3-4-2 WITHOUT changing the tactics. I tried to drag and drop the Defense Icon to the Striker Icon, but they dont swap positions...

 

[Sherkey]

Usually, that should do it. Were you trying to interchange a player who was already playing, or trying to sub someone in? If you're interchanging player positions, it should work. If you're trying to sub in a player who was sent off, then it wont//

 

[bakconhighway]

I was tring to substitue my striker with a defender, and put him to where the sent off defender was playing.
Is there no way of doing that?