World No.1 Novak Djokovic has received a free pass into the third round of the US Open after Jiri Vesely of the Czech Republic withdrew from their match due to a left forearm injury.

The walkover provided the top-seeded defending champion with an extended break to improve his niggling left wrist injury before his next match against either Guido Pella of Argentina or Mikhail Youzhny of Russia.

The 23-year-old Vesely, ranked 49th, beat Djokovic in the second round at the ATP Masters 1000 Monte Carlo event in April in their only meeting, making him one of two top 100 players with more wins than losses against the Serbian.

World No.23 Ivo Karlovic is 2-1 head-to-head against Djokovic.