César Azpilicueta's experience might mean a lot to Atletico Madrid, but at 33 years of age, of course, his quality is not as good as before and he can't play optimally anymore, but because the transfer fee is free, Atletico Madrid is a little lucky.
So far I haven't seen any significant movement in the Atletico Madrid team to improve their team to overshadow next season.
Atletico Madrid luck indeed from this signing as he is a free transfer player. 33 years old is still not too old and I think he will be a big hope for Atletico Madrid defense next season. Atletico Madrid did not make many changes in the transfer window because they identically used the existing squad for next season.
Teams from Laliga that often revamp their squad are Barcelona and Real Madrid because these two teams are far better financially than other teams. For Atletico Madrid, if they don't make big changes, they will likely continue to experience difficulties in the race for the Laliga trophy.