My thoughts are with Leverkusen's fans. I can only imagine what is going through their heads right now 
I knew it was a big mistake when ETH was appointed the job. Alonso worked so hard to raise the club from where it was to a Bundesliga top-flight team. I've no doubt in ETH's abilities. He'll do the opposite. The home defeat to Hoffenheim is just the beginning.
Since the moment ETH was signed as Leverkusen's new coach, I've been positive that ETH wouldn't make the same blunders as at Manchester United and that they would truly be able to bring Leverkusen back to its glory days as Xabi's time at the club.I knew it was a big mistake when ETH was appointed the job. Alonso worked so hard to raise the club from where it was to a Bundesliga top-flight team. I've no doubt in ETH's abilities. He'll do the opposite. The home defeat to Hoffenheim is just the beginning.
But after a few friendly matches, I reconsidered, and more rationally, it seemed it wouldn't be that easy. And finally, in Leverkusen's first Bundesliga match, they were defeated by Hoffenheim 2-1.
Well, that's enough.
Source: Erik ten Hag era with Bayer Leverkusen