Murray admits he will have to improve “dramatically” to mount a successful defence of his Wimbledon title after the world number one suffered an embarrassing Queen's Club exit.
Murray crashed to one of the worst defeats of his glittering career on Tuesday as Australian world number 90 Jordan Thompson put an and to his reign as Queen's champion with an astonishing 7-6 (7/4), 6-2 first round victory.
Thompson, originally beaten in the qualifying rounds, was only playing as a last minute replacement for the injured Aljaz Bedene.
It was the worst possible preparation for Wimbledon, with the grass-court Grand Slam set to get under way on 3 July.
Having reached the French Open semi-finals earlier this month, Murray must have hoped he had returned to form after an injury-plagued first half of the season.
Now the three-time Grand Slam winner plans to go back to the practice courts with coach Ivan Lendl.
"I said before the tournament there was still a lot of work to be done and after the French Open I knew that I was still quite far from where I needed to be," Murray said.
"One tournament doesn't change all of what had gone on just beforehand. So that's why I got back on the practice court quite soon after the French. But I was certainly feeling better in the build-up here than I was going into the French. I would have expected to have played and done a bit better."
Murray has now failed to get past the second round in three of his last four tournaments and has lost before the quarter-finals six times this year.
Murray's defeat left Queen's without the top three seeds as world number three Stan Wawrinka and world number six Milos Raonic were also beaten earlier in the day.
Raonic finished as Queen's and Wimbledon runner-up last year, but the Canadian's hopes of another strong showing on grass were wrecked by Australian wildcard Thanasi Kokkinakis's 7-6 (7/5), 7-6 (10/8) triumph.
Wawrinka was beaten 7-6 (7/4) 7-5 by Spain's Feliciano Lopez in the Swiss star's first match since being thrashed by Rafael Nadal in the French Open final.
So far this year, Murray has been mired in a major slump by his sky-high standards after battling shingles, an elbow injury and the flu.
Meanwhile, tennis superchamp Roger Federer is back on the grass as well, but not at Queens. He beat Japan's Yuichi Sugita in the first round at Halle, in Germany, with 6-3, 6-1 in just 51 minutes.
The Swiss skipped the entire clay-court schedule in order to be fully fit for Wimbledon.
And there he may have yet another heads-on with his all time rival Rafal Nadal, who doesn’t participate at Queens in order to rest and prepare for the All England Lawn Tennis and Croquet Club showdown.