Players attributes

[d.p.p]

Guys

I've been adding players to my saves since FM2015.

Here's my problem: I've always added young players (-10 PA), but left ALL their mental, technical and physical attributes as it came (which means "0"). Now, I was running a few tests where I wanted ONE of these skills to be "20" at the beggining of the save. However, when I do this, the other attibutes are now starting very low and not developing as we could expect from a player with -10 PA. 

I ran tests with the players starting with 100 CA.

 

So, my issue is: How can I set a specific attribute to be player's main attribute without the necessity to set values to the other attributes.

When I leave all the attributes 0, players develop normally for a -10 PA. When I set ONE attribute to be 20, they don't develop the other attributes as expected for a -10PA.

 

I hope I could make myself clear. 

Thanks in advance!