It seems that Xabi is not satisfied with the players he currently has. Especially the current condition of the center players because they were left behind by Beligham who had shoulder surgery. Xabi still sees many shortcomings in his young players. I think this makes a lot of rumors he still wants to buy a midfielder. One of his targets is Man City midfielder Rodri. Real Madrid are ready to bid £100 million to sign the Manchester City star. Although Rodri's condition last season rested a lot due to injury and made Man City not get good achievements.
Source:
https://www.thesun.co.uk/sport/35984346/real-madrid-transfer-rodri-man-city-offer/