Xabi Alonso should simply seek for new managerial position because his team flops in big games and in tougher positions this season. You do think he's happy with the club's stats?
He should be.
If you compare them to the last season, then they might not look that great, but, objectively, the club is doing really well. They still have theoretical chances of winning the league, but even if they don't, the 2nd place in the Bundesliga and reaching the round of 16 in the Champions League is not something to be ashamed of.
The previous season was exceptional and it was pretty obvious they won't be able to replicate that success this season.
But I feel Xabi Alonso may accept an offer from a bigger club if the opportunity arises.