Novak Djokovic admits physical ‘concern’ after first-round win in New York

Novak Djokovic celebrates after defeating Learner Tien (Frank Franklin II/AP)

Novak Djokovic admitted he was concerned by his physical difficulties after battling past young American Learner Tien in the opening round of the US Open.

While a 6-1 7-6 (3) 6-2 scoreline may appear routine, Djokovic looked anything but comfortable in the closing stages of a second set which lasted 82 minutes.