The Scot lost 6-3 3-6 10-6 to world number two Roger Federer as part of a charity event in Glasgow on Tuesday.
It was the first time Murray, 30, had played in public since he lost to Sam Querrey at Wimbledon in July.
“I am in a significantly better place than at the end of Wimbledon and in the build-up to the US Open,” said Murray.
“Walking was a big problem for me [at that time],” he told BBC Sport.
Murray, who slipped to 16th in the latest world rankings, said he was confident of getting back to full fitness, but admitted that it could take time for him to find his best form.
He will travel to Miami later in the year for his regular off-season training block and “hopes” to return to competition at the Brisbane International in January.
The tournament is held two weeks before the Australian Open, the first Grand Slam of 2018, which gets under way on 15 January.
“When I get back on the court again my best form might not come immediately but there’s nothing that’s making me think I can’t find it,” Murray added.
“I’ll come back when I’m ready and 100% fit. I believe I will get back to that.”
Murray also played a doubles match with brother Jamie against Tim Henman and Mansour Bahrami during Tuesday’s ‘Andy Murray Live’ event in Glasgow.
Murray endured a frustrating 2017 season in terms of both form and fitness. He was knocked out of the Australian Open in the fourth round and went on to miss a month with an elbow injury.
He fared better at the French Open, reaching the semi-finals, but lost in the first round at Queen’s Club before visibly struggling with the hip as his Wimbledon title defence was ended by Querrey in the quarter-finals.
Still ranked number one, Murray travelled to New York for the US Open but pulled out two days before the tournament began having failed to recover sufficiently. (Courtesy BBC)