Depending on the outcome of the match between Alexander Zverev and Daniil Medvedev, Stefanos Tsitsipas will either face Dominic Thiem or Roger Federer on Saturday in the ATP Finals semis. The Athens native said: "Thiem plays with a lot of intensity, uses his forehand very well.
Roger is very aggressive. I mean, both very aggressive players but different styles. I would compare that one is just flawless and doesn't use too much of his power to play. The other one is really forcing much. So for me I'm going to -- I mean, I'm going to take it pretty much the same way, both single-handed backhands.
I have played them both. I don't know. It's not much to say about them. I respect them, and I have to play well. I know that, because everything is -- everything counts in the semifinals of the O2." On the reasons why he did not have any break point during the match against Nadal, Tsitsipas added: "I will need some advice from this guy over there (smiling).
Best returner of all times. It's very strange, you know. I like playing lefties. I never had problem playing lefties. My record against lefties, I think, I don't know, in my entire career even outside of ATP has been positive.
There is something about him. I don't know. It comes with a different spin, and that makes it really difficult to return. It's like my brain is used on one certain motion, and suddenly this is like reversed in a way. We all know he's not the biggest server in the tour.
He uses his serve very wise and smart, but he doesn't kill you with his serve. Yeah, it didn't happen today. I'm going to definitely work on it and have more practice sessions with lefties, because most of the time I'm practicing with right-handed players, and work on that more, because for sure I'm going to face him many more times in the future."