Madrid was taking the necessary measures to strengthen their entire squad. But in the match against PSG, we saw again the terrible weakness of Madrid's defense. Madrid bought Alexander Arnold to strengthen the defense. There are also talented defenders like Carvajal, Militao, David Alaba, Mendy and Rudiger. Madrid's defense has a lot of experienced defenders. Even then, if Madrid's defense cannot do well, then it will definitely be considered their tactical weakness. I don't think Madrid needs to buy more experienced defenders.
The two new Real Madrid defenders didn't play the game Vs PSG. The two early goals came in as a defensive blunder by Asencio and Rudiger respectively, with the recovery of both Militaoe and Carvajal that will bring a boost to the CB and RB positions. Where I think Real Madrid needs to strengthen this in defense is the LB, Garcia is not really that kind of player that can handle that position effectively. I'm not going to mention Mendy because I don't even know what his still doing at Madrid.