That's not the issue. The issue is that player skills in the main menu of the World Tour are not their best skills. Here's an example. I just started a new game to test this. First I set starting year to 'Auto' and I picked a random low-ranked player that I'm not interested in. However, while I was scrolling through players to choose my player in the main World Tour menu I noticed Mandlikova's physical attributes (speed and stamina especially) were much worse than what I set them up to be. Screenshot:
Then I exited the game and started a new World Tour game, again with a low ranked player that I'm not interested in, but this this I set starting year to '1985' when Mandlikova is doing well, so I went to Ranking Boards, found Mandlikova and now her skills were different than in the World Tour main menu. Screenshot:
So the issue is that player skills in the main menu of the World Tour are not their skills from their best years. And I noticed it does not happen to all the players, but randomly to some players. Yesterday I noticed it with Graf, but today not with Graf, but with Mandlikova and some other players. So it is very confusing as I don't know what triggers it and it makes it hard to properly balance players. I also noticed, before updating to the latest version, that no matter which numbers I put for Ai Sugiyama (and some other players) in the Players.ini file her physical skills would always end up low/below-average (at least in the World Tour main menu) and this is a player whose best rank is #10 if I remember well, so this shouldn't be an issue.
I think there is some ninja hidden bug happening with phyisical skills but I cannot figure out what causes it.