I think Sevilla should not rush in sacking Jose Luis Mendilibar. Because Mendilibar was actually an important figure who brought big changes to the Sevilla squad last season. Sevilla even avoided the relegation zone in Laliga and managed to win the Europa League title with Mendilibar.
Even though Sevilla haven't shown a good performance this season, I still think that giving more time to Jose Luis Mendilibar would be much better. Because currently Sevilla also has an important match in the Champions League. And of course changing the current coach is a bad decision.
Even if Diego Alonso could become a good coach for Sevilla, improvements will not occur instantly. Everything definitely requires adaptation and is quite a long process. And actually, Sevilla currently doesn't have enough time to adapt to a new coach. Because a busy match schedule and a change of coach will only make things worse.
Sevilla in the Champions League currently has not experienced a defeat nor has they won. Two matches only ended in draws. And I think that's still quite better than losing. But I'm also curious whether Diego Alonso will really make a drastic improvement in Sevilla's performance or if it will actually get worse. Let's see.
Personally I don't think Sevilla have a coaching problem so they shouldn't be in a haste to sack Luis Mendilibar considering how well he has performed so far in with the team, last season he helped them finish reasonably in the league and even qualified for the UCL something that initially felt difficult for the team, so he is considerably still worth giving some time maybe he could improve.
Although Sevilla hasn't been at their best this season but they aren't at their worse either and the season is still yet halfway so there is still enough room for improvement, he should only improve in his tactics and his formation, they may most likely start getting some wins enough to take them up the table again. The frequent change of manager could affect the teams performance and this time it may most likely not turn out really fine as the teams is already getting along with their currently manager, any changes will mean a start all over again and this is not healthy especially for their position in the UCL.
I am pretty sure that Diego Alonso is the new coach of Sevilla. I am not sure if this was a good decision or not. But I am sure that they were not performing as well as they should. The only saving price for the coach was that they were able to win the Europa League title the last season. But now we know that they are performing in the Champions League competition. And there is no way they are winning the Champions League.
At the same time the way they are playing right now, they also don't seem to be winning the La Liga title as well. If the decision was actually an improvement or not, we will be able to know that later. And I absolutely agreed that improvements are not going to come instantly.
I don't care too much about Sevilla's performance but at the start of the season I thought Barcelona and Real Madrid would start well in La Liga and they would go on to compete brilliantly. But although Barcelona team is performing well, I think Real Madrid team is not able to perform as they want.