Injury is one of the risks that can occur when conditions on the field are not conducive, so that playing on the field becomes unhealthy and unpleasant. However, Xabi Alonso must still have a backup strategy to still win the upcoming match in January next year. At least there is still sufficient time to recover the condition of the injured players, and there is sufficient time for Xabi Alonso to find a solution to the problem that is currently affecting him.
Bayer Leverkusen have been quite lucky so far in my opinion because they are one of the teams whose players have had very few injuries, so their performance has been very consistent from the start of the season to the middle of this season.
Their players are still very fit, and indeed player injuries are often a scary thing even for a team that is said to be strong, even though they are said to have players of the same quality, both core and reserve players, there will always be a decline in performance as experienced by Manchester City because one of the main players has not been able to compete so far due to injury and also what has been experienced by lots of clubs.
Xabi Alonso certainly does not expect any injuries to his players until he can ensure the Bundesliga title and also achieve maximum performance in competitions in the European league, but unfortunately no one can predict exactly what will happen in the future.