The painful defeat to PSG was a heavy blow to Real Madrid, who were overconfident in the Club World Cup but were humiliated by a crushing score. Xabi Alonso had to pay a heavy price for the experiments carried out in his squad, several players looked confused and often made mistakes that made it easier for PSG to dominate the match.
Since Toni Kroos retired, Real Madrid has lacked a central midfielder capable of controlling the game and supplying the ball to the forwards. Mac Alister could help fill a gap in Real Madrid squad even though his quality is not comparable to Kroos and Modric, but Liverpool will not let go of their mainstay player just like that, especially since they are very disappointed after TAA was hijacked by Real Madrid on a free transfer.
This isn't everything, and this rather embarrassing defeat is a common occurrence in football, as we also saw PSG humiliated by Chelsea in the Club World Cup final. Mistakes can happen at any time, but the most important thing is that they can make changes, and I'm sure Xabi Alonso has learned to understand situations like this. Midfield is a crucial position for Real Madrid right now, as Toni Kroos's retirement has left no player capable of replacing him. Mac Alister is Real Madrid's next target, but Liverpool certainly won't let him go easily. Xabi Alonso still has a lot of work to do, as Real Madrid's overall form hasn't fully recovered and still needs several players to perform at their best.