The Spaniard's loss to Alexander Zverev was not something many expected to happen but truthfully, the German did give Alcaraz a fair amount of trouble in the past. He bested him at the ATP Finals not too long ago and added another impressive win, especially with the way it ended.
It wasn't a very good match by the two-time major winner, who struggled with control for all but a set and a half, and that' simply was not good enough to get a place in the semi-final. One thing that might have contributed to that was not having his coach Juan Carlos Ferrero there.
It's not a situation in which he didn't find himself before, but he did look rather clueless at times in this match, failing to really find a solution, especially against the serve of Zverev. Asked about that after the match, Alcaraz rubbished the suggestion completely, explaining that it had no effect.
"No, it didn't affect at all. As I said, I was playing great tennis, you know, without him. I had someone that is a pretty good coach as well. I trust him 100%, as I said before the tournament began. It didn't affect me at all."
Whether it did influence him or not remains to be seen, but it's clearly something that he's not used to. Ultimately, the responsibility for winning the match falls on him, and he didn't show his best tennis.
It came in spurts, but that's not good enough to beat a really good player who was having an amazing day. The serve was the biggest obstacle for Alcaraz, denying him a chance to adopt pressure early, and the inconsistencies from the baseline pushed it out of reach. It was a tough loss but a valuable lesson for the youngster.