As far as I remember, no Union Berlin players were released last summer and their squad was still intact like the previous season and if anyone left it was a player who was not included in Urs Fischer's plans. Key players such as Sheraldo Becker and Kevin Behrens are still at Union Berlin and both were top scorers last season for Union Berlin. But not only that, Union Berlin also brought in quite good players such as Robin Gosens from Inter and David Datro Fofana from Chelsea. Of course, Urs Fischer brought in this player to strengthen his attack line and midfield, but it hasn't been successful enough until now. Union Berlin still has a long way to go in the Bundesliga and they can actually still enter the top 10 if they show the same performance as last season.
The problem are the new players. Union Berlin had previously brought in unknown players. Or well-known players who have not been in the A-Team at the respective club for a long time. They have slowly integrated these players into the team and built them up. With the purchase of Gosens and Fofana, they have broken with this philosophy. They were allowed to play straight away and the players who had always played last season sat suddenly on the bench. That brought turbulence into the entire team. If there is then a lack of success, the first cracks appear in a team-unit that has not grown together.
But now we will see a new coach who will be able to deal with that.
It makes sense if things happen like that because they were much better with the same squad last season. But as coach Urs Fischer certainly wanted more, but unfortunately it didn't go so smoothly. On the other hand, if I'm not mistaken, Union Berlin also brought in Leonardo Bonucci from Juventus as a free agent and until now he has only had a few opportunities while playing for Union Berlin so far.
So Leonardo Bonucci's experience should sometimes make Union Berlin's defense easier to penetrate and that is why the new players are the problem you mentioned earlier. I would really regret it if Urs Fischer was fired, but of course the owner of Union Berlin doesn't want to take too long to make a decision, especially as staying in the Bundesliga is the main choice rather than being relegated again this season.