I think every Football Manager out there has tried to retrain a certain player to a additional player role in his footballing career. Reasons can be to make sure newly signed players fit the own tactical formation or you want to add some player roles in order to have some backups when injuries occur.
My main reason was that I signed Griezmann for a fee less than £30 millions, in the winter transfer window and I decided that I want to play with 3 strikers upfront and no wingers anymore at the end of the season.
I mean wingers are great and you can find plenty of them, but when I start setting up a world class youth development I really like not having to much different player roles in my first team. With players with 3 central strikers and 2 central midfielders make is much more easier to get the youngsters at the club some playing time in a position they are familiar, without letting the first-teamers with less playing time.
The problem with the new tactic is that I had 2 really promising or already world class Regens who played at the wide positions in my first team: Macias and John.
In order to guarantee them some playing time before I get an acceptable offer from one of the high spenders in FM I decided to retrain them both as false nine on the 10th of august.
But what affects the adapting to a new player? Personally I think it's playing time and and mentality. Playing in the new role always make it easier as he can learn from his own mistakes during the match, so I decided to give both some similar playing time.
There is no such attribute like adaptability like we have on the staff in FM to determinate the players strength in adapting to new position (or at least not visible). The only mental attribute that is (more or less) available and is professionalism, which can used in player searches. To make sure I looked up the exact attributes with MacAssistant the exact attributes of the two players:
As you see in the table above there is a huge difference in Professionalism, so I expect Macias to do a lot more better regarding the familiarity of the new role. With the progress of the game the players had following statuses to new the playing positions:
As you see Macias is natural at his new position quite faster with less playing time. But this is nowhere compared to the difference in the professionalism. I think the biggest part in getting used to a new playing position is to get as much playing time on the new position. Although I have to add that Macias had to small injuries (out for 11 and 6 days) as well.
FC Barcelona did like the development of Macias so well, that they decided to spend £123 millions on him in the upcoming winter transfer window: