Juan Martin del Potro's press conference after his 6-4, 7-6, 6-3 win over Andreas Seppi
Q. Can you give us an update on your medical situation with your ankle and your knee.
JUAN MARTIN DEL POTRO: The ankle is good and the knee is not good. But I'm allowed to play. Still bother me in the left outside of the knee. I couldn't do the MRI. That's what I need for a specific result of the knee.
But the doctor says nothing too dangerous, and that's positive.
Q. How much pain is the knee giving you when you play? Is there much?
JUAN MARTIN DEL POTRO: Yeah, it's bother me a lot. I couldn't extend 100% the knee. And the tapes for today help me to be careful in some movements. But is not enough.
But I have one day and a half until my next match, and I will do all the treatments to see if I can be better.
Q. Unfortunately you have experience with injuries. Aren't you afraid to maybe take a huge risk playing on this knee?
JUAN MARTIN DEL POTRO: Yeah, yeah, I have many injuries in the past. But this time I think I don't have luck, and that's it. I was winning so easy the third round. Just for run a dropshot, I twist my ankle and hyperextended my knee.
And you can see all the players are doing some strange movements and feel something wrong. But I think is not too really dangerous, and that's positive for me.
Q. Do you enjoy your game while you're playing? A lot of players these days seem to not enjoy to play tennis.
JUAN MARTIN DEL POTRO: No, I am enjoying. I think I play really well. Seppi is a really good player on grass. I think he can take this surface for the favorite surface.
Was really close match. I won a tiebreak. Then in the end, I play better.
I was lucky when I serve break down in the last game. But I think I'm playing better and better match by match.
Q. Your next opponent is David Ferrer. You have a 6‑2 losing record against David. You played him at Wimbledon last year in the quarterfinals. What do you think you have to do this time to beat him this time?
JUAN MARTIN DEL POTRO: Well, David is doing a fantastic season at the moment. He's I think No. 3 in the world after this tournament. He deserve to be there, for sure.
He was a good player on grass. When you check the papers or you see Rafa and the rest of the Spanish guys, you say they are better on clay. But David, he is a very good player on all surface.
He made quarters last year here. He beat me. Now we have the chance to go to the semis for the first time. But I think it's going to be a really, really tough match for me. I hope the knee, it's better after tomorrow, then I will have to play my best tennis.
Q. David said there probably isn't a player left in the draw who isn't playing with an injury. He also has problems with an ankle and his big toe. Do you agree with that, that most of you play with injuries?
JUAN MARTIN DEL POTRO: Yeah, I think so, yeah. Yeah, we feel different injuries or sometimes something bother our body. But you have to keep strong and try to manage it, the pain, the best we can.
I think in these kind of matches, in quarterfinals, all the players feel something. We already play four matches. A five‑set match also.
Is interesting for us. But I think we are okay for the rest of the tournament.
Q. We've talked a lot about your injury. One thing that would be good to talk about is you made the Wimbledon quarterfinals for the first time in your career. How special is that?
JUAN MARTIN DEL POTRO: Is very special. I'm so, so happy for be in the quarters for first time. I'm so exciting to be in that group, the only eight players going to be playing the quarters.
I reach quarters here, and all the Grand Slams, as well. It's a good number for me. I'm really like to play on grass at the moment. I think I improve my game here. Also I have good memories from last year during Wimbledon and the Olympics.
Q. You've said you are feeling better on grass this year. Maybe one day you will go to the net more often than now?
JUAN MARTIN DEL POTRO: Maybe one day (smiling).
Q. How important is Wimbledon as a tournament to you to win? Would it be up there at the top to win it one day?
JUAN MARTIN DEL POTRO: Yeah, all Grand Slam are special. Wimbledon has something different than the rest. My favorite is still the US Open.
But be here in quarters, it's amazing. Also it's a big challenge, trying to win another Grand Slam, for sure.
We fight for that. We are eight players in quarters with the same challenge in this moment. Winning here on grass for one Argentinian guy could be very, very special.