Playing a player outside his position!!!

The reason I ask is cause I have a DC DMC player that I usually use as a sub whenever I need to change tactics to add more players in defense since I play with three defenders. I have two starting DMC players that are higher rated than him and after comparing them with the player I mentioned they are better and higher rated than him even in all defense attributes. Logically this players should perform better even as a DC even thou they are only defensive midfielders. Will the game punish me if I play them as DC and save a sub. Why do we have to train this players for a new position just so the "DC logo" will appear when they already have the attributes and skills. I'm a little confused can someone pls explain. Thx

I play with players out position. I can assure you, that sometimes, the benefit is bigger than the punishment, Typically a yellow triangle means -1% possession and a red 2%, and that, "th player can not perform well". Ive been in my next to 60 seasons using ST's as AMC's, AMC's as MC's, DC's as DMC's and all depend of the internal settngs of the players.

Lets say that all the players work in same way, a MC can stay in the place as MC but do not appear, so? don't work, and thats all. A ST can barely score despite be a ST so, you have to test what a player does in this different position, and is works, works, thats all dude.