"I think it's going to be dangerous if I'm not careful in the next few days," he said. "But I played my best tennis in this tournament so far and I'm so happy to be in the semis."
"I have my knee problem, but always the opponent, the other players, can have different injuries, too," del Potro said. "You have to be strong, more than the rest."
"Thinking about the Djokovic match, I need to practice tomorrow for sure," del Potro said. "I'm confident with my serve and expect everything good after tomorrow. I'm positive and I'm not thinking too much in my knee."
Tyle od Del Potro
"Coming into the semifinals, I feel physically fresh," Djokovic said.