Question from a newbie/ex-Fifa convert

Got spanked at Pro Evo on a games night a few weeks ago but loved the gameplay so bought the game.. sorry if this is the wrong place/has already been answered but I couldn’t find an answer on google or here - however I was only searching for about 5 minutes...

It’s just about editing teams - if I edit a team when I have already started a Master League (I haven’t started one yet for this very reason) do the edited changes take place in the existing ML or would they only affect a new ML?

So...

Question from a newbie/ex-Fifa convert