Djokovic Has Slight Fitness Concerns

Long exchanges in opener take a toll on him, Medvedev melts down over dispute

- 

NEW YORK - Novak Djokovic fears his lack of physical conditioning may come back to haunt him as he chases a record 25th Grand Slam singles title at the US Open.

The 38-year-old Serbian superstar made a winning start to his latest tilt at glory on Aug 24, defeating US teenager Learner Tien 6-1, 7-6 (7-3), 6-2 in 2hr 25min on the Arthur Ashe Stadium court.

But Djokovic, who needed a lengthy medical timeout to treat a blister on his right foot between the second and third sets, admitted afterwards he was worried by a sudden loss of stamina during the second set.

"I started great - just over 20 minutes, first set, I felt really good," he said.

"Then some long games to start the second set... I really was surprised how bad I was feeling in the second physically.

"There are positives but also things that hopefully won't happen, in terms of how I felt on the court physically in the second set.

"It's slightly a concern. I don't know. I don't have any injury or anything. I just struggled a lot to stay in long exchanges and recover after points."