What happen to my player?

[Tactician]

The percentage is shown relative to the level concerned. The same applies for the number of stars. Your player has the same attributes, but had a drop in percentage as he will now play in a team in a level above as compared to last season. When a team is promoted to the next level, each player that is in the team lose 20% in the displayed quality, but they don't lose skill points. The percentages shown give you an indication of how good your players are relative to the level you are now in.