I rather agree with @Ahlony
Only one new player, can change the "balance", the "chemistry" of the team.
Maybe needs time to work together, play some games, observe if someone performs better in the side position (2 MCs or DCs or STs for example, the right and the left position).
There is another similar thread
http://forum.topeleven.com/top-eleve...w-version.html
but I don't see how the new update can affect the performance.
Even if there wasn't any, still many managers could report that their team, this season, after many successful previous seasons, cannot perform well (for no reason).