Pain-free Murray still has Open passion

Five-time Australian Open finalist Andy Murray says his health and family will dictate any retirement plans, not whether he can return to grand-slam glory.

The 35-year-old former world No.1 ramped up preparations to play in his 15th Open with a comeback win over China's Zhang Zhizhen at the Kooyong Classic on Wednesday.

Murray was out of sorts early but fired up to take the match in a super tiebreak 2-6 6-3 10-2.

The Scotsman moved well in the hot conditions in Melbourne, finding his groove in the second set after his off-season was interrupted by illness.

He showed no signs of the cramping which hindered some of his matches last year.

"I felt pretty rushed at the beginning and a little bit slow on my feet but once I started to adjust to the court I started to hit the ball quite nicely," Murray told reporters.

"I had some issues with cramping in the middle to end of last year which was frustrating.

"I played (Matteo) Berrettini at the US Open and it was a four-hour match and I was fine.

"I'm still not sure of the reasons behind it (cramping) but I've made a few changes and done a lot of work in the off-season to give myself a chance to be OK."

Undergoing two rounds of major hip surgery in 2018 and 2019, Murray has not won a title since 2019 while his most recent major came at Wimbledon in 2016, the same year he successfully defended his Olympic singles gold medal.

He reached the Australian Open final five times between 2010 and 2016 but in heartbreaking fashion never managed to lift the Norman Brookes trophy.

While his ranking has climbed back to world No.49, the ageing Murray does not appear likely to be a contender for a fourth grand-slam title.

But that is not going to force him into retirement.

"As long as my body is holding up well and I am able to train properly so that I can go on the court and perform to a level that I am still enjoying then I will keep going," the father of four said.

"I don't know on a time frame or anything like that - if I have the support of my family to keep doing it then I will keep going, if I'm healthy.

"The last seven months, there has been frustration in there but I've enjoyed it because when I get up to practise I don't worry about an injury.

"I'm not waking up with lots of aches and pains like I was the last few years - I found that hard."