The main issue that Xabi Alonso should seriously address is the defense, which so far hasn't looked very solid. Having a sharp attack is pointless if the defense is porous, it won't lead to success. Therefore, Xabi Alonso must find a solution to encourage Raul Asencio, Dean Huijsen, and Trent Alexander-Arnold to reach their best potential.
Last season was a bad season for Madrid. If I am not mistaken, they had 51 injuries. Only 2 players managed to stay fit until the end, Modric and Guler. According to the doctors' analysis, most of them had muscle injuries. This condition indicates that the players have a very heavy workload. As of now, I do not know about some players who are suffering from long-term injuries, I hope they recover soon. Because Xabi is indeed building a team. He should take advantage of this transfer moment to add a center-back and a central midfielder who are ready to be used.
no Real Madrid defenders are injured except for Bellingham.
So it is likely that Real Madrid's entire defense is now ready, meaning Xabi does not need to worry about starting the league later and they can return to playing the key players they really need.
So far, there has been no news that Real Madrid will add more players to their defense.