A visibly emotional Andy Murray admitted he is unsure how much longer he will be able to play competitive tennis after making his latest comeback in Brisbane.

The former world number one appeared to fight back tears as he reflected on his battle to resume his career following hip surgery, saying it had been "really hard".

Murray progressed to the second round of the Brisbane International on Tuesday with a 6-3 6-4 victory over Australian wildcard James Duckworth, his first match since bringing an early end to a truncated season in September.

Speaking in his on-court interview after the match, the Scot said of his recovery: "It's not easy to sort of sum up in one sentence or one answer, it's been really hard; 18 months, a lot of ups and downs, it's been tricky to just get back on the court competing again.

"So I'm happy I'm back out here again, I want to try and enjoy it as much as I can and just try and enjoy playing tennis as long as I can. I don't know how much longer it's going to last but we'll see."

It was in Brisbane last January when Murray decided that he would have to undergo surgery for a problem that first surfaced in the summer of 2017.

The two-time Wimbledon champion managed just half a dozen tournaments in 2018 and spent several periods during the last six months in Philadelphia working with a reconditioning specialist.

Now ranked 240 in the world, he appeared positive about his meeting with Duckworth, who is six places above him in the ATP rankings.

Murray said he thought he "did quite well", but admitted he may have been "a little bit nervous" at the start of the match.

"I think for a first match of the new year after quite a long break it was all right," the 31-year-old said.

His movement out wide to the forehand still appears to be compromised but Murray struck a more upbeat note in his press conference later, telling reporters: "I was nervous, but I like nerves. Today I felt like I saw the ball better versus, say, the middle of last year.

"I don't feel apprehensive about my hip. Today I didn't really think about it at all. I was in a little bit of discomfort, but I didn't feel (the hip) on any movements for my shots. It didn't affect my play that way."

Murray broke Duckworth three times in a match that lasted just short of 90 minutes, the first in the sixth game of the first set.

But the 26-year-old Australian fought back, breaking Murray in the seventh. Murray returned fire to break back in the eighth game before serving out the set.

Duckworth kept up the pressure in the second set, forcing his opponent to fight back from four break points in the second game. But Murray held on and eventually broke his opponent's serve in the ninth game before serving out for the win.

Murray will next face number four seed Daniil Medvedev, ranked 16 in the world, in the second round.