Re-training players for a new position

I've been training my hot prospect DL for the WBL position since more than a season now. Very slowly it improved from awkkward to competent first, than to accomplished. I was happy with accomplished and stopped his training. Only 1 week later it dropped back to competent, then I had to re-train him for another 3 months until it went up to accomlished. My question is, do I have to keep training him in that position for it not to drop back? If I stop training him in that position, is it going to drop back to nothing eventually?

Thanks.

Yeah, you have to keep training him in that position or keep playing him there

That really s..cks then. What if I want to train him for ML as well? There are players in the original DB that are accomplished in like 4-5 different positions. But the newgens are never like that. They can play only in 1-2 positions, and if what you're saying is true that means you can add only 1 more position to it.

That's right bleventozturk.