yes, as Stepenwolf said, training a special ability it's only training.
The drills don't matter.
A fast trainer can gain 1 point for a pack of drills with -15 to -18 condition loss.
The gaining of a player depends from the internal "hidden" talent but from his stars too.
You should start to give the sa when he was 5* player, not now.
If you insist, this gonna cost you about the double or more greens.
you can wait the next season, when he is gonna "lost" one star.
Meanwhile read some useful threads in Tutorials & Guides section.
This gonna save a lot of sources (tokens/packs) for your future.