Briton Murray suffered his first defeat in his second match back from a long break following his Wimbledon triumph, falling 6-4 6-3 to the talented but inconsistent Gulbis in the third round.
Murray has only the Cincinnati Masters to tune up for Flushing Meadows in little over a fortnight but he was not panicking after being on the receiving end of an inspired display.
"You can't expect to play perfect straightaway. It takes time," Murray said.
"I was playing a very good player today, someone that gives you very little rhythm on the court ... but I actually thought I hit the ball better today than yesterday."
After resting up following Wimbledon, Murray had a training block in Miami en route to Montreal.
"I had a bit longer to prepare this year," Murray said as he reflected on his run to last year's US Open crown.
"But maybe I just need to make sure I get a few more matches in practice in the future."
While his singles campaign has ended, Murray and fellow Briton Colin Fleming combined in the doubles to beat the fourth seeds, Leander Paes of India and Czech Radek Stepanek, to advance to the quarter-finals.
Teaming up with Fleming was a late decision and while it may not have been part of his original plan, another match away from the main spotlight may prove a blessing in disguise.
"The goal is to try and peak at the US Open," Murray said.
"But to do that you need to make sure you prepare yourself well and obviously I would have liked to have done better here.
"All I can keep doing, is trying to keep improving every day. Hopefully by the time the US (Open) comes around, I'm playing my best tennis."