Juan Martin del Potro's press conference after his 7-5, 7-6, 6-0 win over Grega Zemlja
Q. How was the game today? Court 12, have you played before?
JUAN MARTIN DEL POTRO: Did you see the match?
JUAN MARTIN DEL POTRO: Did you like it?
JUAN MARTIN DEL POTRO: Why not?
Q. Too slow.
JUAN MARTIN DEL POTRO: Oh (smiling).
I think I play well.
Q. Yeah, you play well.
JUAN MARTIN DEL POTRO: Thank you.
Q. But you were still slow.
JUAN MARTIN DEL POTRO: Yeah, it's my game, my way of the game. Slow, calm, patient, no?
Q. How is your knee?
JUAN MARTIN DEL POTRO: Well, I will see the doctor after here, because I was going for the dropshot and I twist my ankle. I did like hyperextended my knee, as well. It was really painful. I was a little scared at that moment.
I finish the match very quick. Now I start to feel something in my knee and my ankle, as well. I will check with the doctor very soon.
Q. It was a rather nasty fall, crashing into the chairs.
JUAN MARTIN DEL POTRO: Yeah, yeah, but I didn't saw the ball. I didn't see anything. Just I was fell down on the floor. I'm very scared about my knee and ankle.
But after the tapes, I feel more confidence with my knee. I could finish the match.
Q. Two sets and 5‑Love, would not have been a good time to quit.
JUAN MARTIN DEL POTRO: Of course not. But I was serving, so I was focused on my serve, trying to close the match in that game and then have the time to recovery.
Q. None of these are old injuries, the ankle and the knee?
JUAN MARTIN DEL POTRO: No. Is my first time, yeah. But on this surface can happen. It's very normal.
Q. The first two sets were so close. The third set you won 6‑Love. What do you think the difference was in that third set?
JUAN MARTIN DEL POTRO: Well, I think he serve really well on the second set. He made like 20 first serves in a row, and I only won a point during the tiebreak. He was very, very tough for me trying to break his serve.
In the tiebreak I play better like you have to play in this surface. Only the most important moments you have to play better than the opponent and then try to take the opportunity to win. That's what I did today.
Q. Have you played Seppi very often?
JUAN MARTIN DEL POTRO: I played against him last year here in the Olympics.
Q. What are your thoughts on that?
JUAN MARTIN DEL POTRO: He beat Nishikori, really tough guy. And Seppi plays well on grass. He's very fast and he play flat all the shots. All the guys are dangerous in 16, you know.
Q. You've made the fourth round now three years in a row, and the two years before that was Nadal and Ferrer. Now it's Seppi. Do you think it's a better chance to reach the quarterfinals?
JUAN MARTIN DEL POTRO: I'm going match by match and will try to fix my ankle and the knee first. And all the matches are a big opportunity to stay winning. But the opponents are good, and you can see you have a very good example here in this tournament. All the guys are prepared for beat all the players and they can surprise everyone.
Q. Is the grass a problem to you?
JUAN MARTIN DEL POTRO: Not at the moment, but maybe in the next match. I will see.
Q. What do you do if you're not playing tennis? How do you relax?
JUAN MARTIN DEL POTRO: I don't know. What can I say?
After the press, I want to take a massage, good massage.