Djokovic voices physical concerns after US Open win

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 Sunday, 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,” Djokovic said.
“Then some long games to start the second set... I really was surprised how bad I was feeling in the second physically.
“We had long exchanges, but also, I kind of dropped my level and made a lot of unforced errors and kind of got him back into the match.
“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.