There's Carlos Alcaraz and Novak Djokovic, and then there's the rest of the ATP Tour.

That's according to 2020 US Open finalist Alexander Zverev who is coming off a 6-3, 6-2, 6-4 defeat to Alcaraz in their quarterfinal clash on Wednesday.

Although he believed he was still in the contest during the first set, the German eventually felt something in his hamstring glute which all but took away his serve in the second and third set.

That doesn't take anything away from Alcaraz, however, and having also played and lost to Djokovic in Cincinnati last month, Zverev believes the duo have separated themselves from the rest of the pack.

“Well, I mean, I played Novak in Cincinnati, I played Carlos here. I think they are very, very similar from the level of the game,” Zverev said in his post-match press conference (via Tennis 365). “There are some things that Novak does better, there are some things that Carlos does better.

“I think they are at a level of their own at the moment. Yeah, the other guys gotta catch up. That’s as simple as that.”

In fairness to Zverev, he is 3-3 against Alcaraz in their head-to-head record. However, the Spaniard has won three of their last four meetings as Zverev commented on his ability to win big points.

“If I remember correctly, I think we were in the rally once, and I missed a backhand down the line,” Zverev explained. “I think maybe I shouldn’t have gone for that because I was winning quite a lot of rallies until that point. Second break point I don’t remember, to be honest. I mean, I don’t know. It’s tough to say, because there was only a few important moments in this match, to be honest, which he played well. Maybe I went for a wrong decision, wrong shot, in a way.

“But I thought even though I lost first set I thought it was going to be a competitive match. I thought my level was there. I thought his level was there. I thought it was going to be a fun one. I think first or second game, I think first game already in the second set I felt something wrong. Then I didn’t give up, but there is very little you can do in a way against Carlos then.”

Carlos Alcaraz and Novak Djokovic could be set for another final showdown if they win their respective semifinal clashes on Friday.

Alcaraz battles 2021 winner Daniil Medvedev while Djokovic faces American Ben Shelton.