The 26-year-old world number four called an early end to his 2013 season after playing a Davis Cup tie in mid-September to have surgery on his lower back. (Agencies)
Murray has been trying to lower expectations as he begins his comeback from injury and was not too concerned at losing his first match in the Mubadala world tennis championships event at Zayed Sports City.
"I moved well in the first set, especially once I got into the rallies," he told the National newspaper after a 7-5 6-3 defeat to French world number 10 Jo-Wilfried Tsonga on Thursday.
"I didn't feel slow at all. In the second, I slowed down slightly, but that's something that is going to get better by playing matches. I can't expect to feel great for long periods of matches straightaway.
"But it was a good workout. You want to play your best, but you need to be realistic and patient. I will play better tomorrow than I did today.
"I was hitting the ball okay, moving well for the most part. Moving is the most important thing. I just need to be able to do it for a longer period. I just felt like I hadn't played a match for a while."
Murray missed this year's French Open due to a back injury but recovered in time to become the first British man to win Wimbledon for 77 years.
The Scot lost his U.S. Open title in a quarter-final defeat to Stan Wawrinka and then played in Britain's world group playoff against Croatia before deciding to have the operation.
He has spent the intervening months in Florida recuperating and will make his return to the ATP tour at next week's Qatar Open in Doha.
"Some parts of it were nice. I got to spend a lot of time at home, which is something we don't get to do much," he said of the layoff.
"It wasn't that difficult for me, mentally, to be sitting because it wasn't like I was playing one day and twisted my ankle and couldn't play or my back just went one day. I feel fresher," he added.
The 26-year-old world number four called an early end to his 2013 season after playing a Davis Cup tie in mid-September to have surgery on his lower back.