The defending champion and Olympic gold medallist was downed in straight sets by the world number 38 with the US Open less than two weeks away.
"When going into the big tournaments, sometimes I've won tournaments in the buildup and it hasn't helped me," Murray told reporters.
"This year at Wimbledon, I lost in the first round at Queen's and made the final there for the first time. I have won Queen's before and not done well at Wimbledon.
"So it doesn't normally have that much bearing. But obviously I would have liked to have done a bit better this week."
The US Open starts on August 27 at Flushing Meadows, New York.