Three-time Wimbledon finalist Andy Roddick has cited his recent hip flexor injury in withdrawing from the Indianapolis Tennis Championships starting Sunday.

The 26-year-old dealt a blow to the event, which will now feature 2007 winner and 2008 finalist Dmitry Tursunov in the top seeding spot ahead of Israeli Dudi Sela, hero of the Davis Cup quarter-final win over Russia.

Roddick has now delayed his return to tennis for the second time in three weeks after opting out of the US Davis Cup tie against Croatia, which produced a loss for the 32-times champion Americans.

Roddick's coach Larry Stefanki delivered the news to organisers, saying his man is still hurting from the problem which also bothered him in his loss at Wimbledon to Roger Federer two weeks ago.

Roddick has given no indication of when he will re-join the Association of Tennis Professionals (ATP), with the clock ticking on the US Open starting August 31 and a pair of Masters 1000 events in Montreal and Cincinnati set for August.