World number one Novak Djokovic has insisted that he knows how to execute his game against upcoming opponent Marin Cilic at the US Open.
The Serbian will face the defending champion in the semi-finals at Flushing Meadows after claiming a four-set victory over Feliciano Lopez in Tuesday's quarter-finals.
Cilic secured his place in the final four earlier in the day, but he was pushed to five sets against Jo-Wilfried Tsonga.
"[Cilic] hasn't lost a match, you know, 12, 13 matches in a row, so I'm sure that he feels confident," Djokovic told reporters. "He won today a really close match. A couple of five-setters he had already in this tournament, but he has a big serve.
"I think around 30 aces he had today, so the serve gets him out of trouble. I know him very well. I have played with him many, many times. We are great friends. Great guy. I know what to do and I'm hoping I can execute the game plan and play my best."
Djokovic won his first and only US Open title so far in 2011.
