Andy Murray has admitted to feeling heavily fatigued in his surprise defeat to Teymuraz Gabashvili in the Washington Open.
The world number three, who received a bye into the second round, suffered a 6-4 4-6 7-6(4) loss against his unseeded opponent.
Having opted to play an extra tournament in the build-up to this month's US Open in New York, Murray admits that he will need more time to hit top form.
"I was exhausted at the end because my body was really tired," the Scot is quoted as saying by BBC Sport. "But it wasn't like I was blown off the court in a match that I had no chance of winning.
"It was the first hard-court match for four-and-a-half months with only four or five days of preparation, so I was happy with how I moved and did certain things on court."
Murray will now play Masters events in Montreal and Cincinnati over the next fortnight ahead of the season's final Grand Slam.
