The only thing that scares me about Xabi Alonso is the fact that if Real Madrid doesn't get some useful results right away, he'll be eliminated very quickly, because we know that Real Madrid has to win, always, and if you don't, you'll be eliminated easily.
Real Madrid is a club that doesn't accept failure from its coach, and that's why they sacked Ancelotti and signed Xabi Alonso. The Real Madrid board expects Xabi Alonso to change the performance of Real Madrid in the upcoming La Liga season, but if Xabi Alonso fails to perform well in La Liga with Real Madrid, the Real Madrid board will likely sack him because he didn't perform the way they expected him to perform.