Poulter double-bogeyed the 14th and 15th before withdrawing
England's Ian Poulter was forced to withdraw after 15 holes of his second round in the US Open because of an apparent wrist problem.
Poulter, who had earlier complained about an injury, three-putted from four feet at the 15th and was seven-over for the day and 14-over for the tournament.
Playing partner Luke Donald said he had no idea why Poulter did not finish.
"He just said he was off so he left us," Donald said. "He just said goodbye and good luck."
A United States Golf Association (USGA) official said that he was aware that Poulter was having problems with his wrist and Poulter confided as much to Paul Casey, the third Englishman in the trio.
Poulter, who opened with a 78 on Thursday, finished tied for 36th at last year's US Open at Oakmont and now has just one top-20 finish in five starts in the season's second major.