Murray has been far from playing his best tennis in recent months. Four straight defeats. Eight defeats in his past 12 matches since the start of the US Open in August.

But remember: the fact the 36-year-old is even playing at all remains remarkable.

Five years ago at Melbourne Park, the Scot tearfully said he thought he would have to retire later that year because of impending hip surgery.

The resurfacing operation involves a metal cap being inserted into the socket of the hip where it meets with the femur. No singles player had ever returned to the tour from that procedure.

Murray did return - later in the 2019 season - and incredibly won an ATP title in Antwerp a few months later.

In the past four seasons he has produced a host of memorable moments, broken back into the world's top 40 and won more titles.

A deep run at a Grand Slam continues to evade him and it understandably seems difficult for a player of his previous stature to accept he cannot compete to the standard which he would like.

Murray says he will stop playing when he is no longer enjoying it, but also has a farewell point for when he wants to bring the curtain on his illustrious career.

"I haven't made any definite decisions on that. But I've spoken to my family and my team about it," he added.

"They're very aware of how I feel about things, where I would like to finish playing, when that would be."

As we have seen over the years, things can quickly change in his mind but when it comes to the day most athletes fear - retirement - it is going to come down to two things.

Results and fitness.

Now, after an arduous journey to regain the latter, it is the former which has left him questioning his future.

In a frank but sombre news conference after losing to Etcheverry, he said: "I haven't gained in belief from today's match that at some stage I'm going to start playing really well again or winning tournaments or getting to the latter stages of major events.

"Last year was a slightly different story. Physically I held up well against two really good players. It is a very different situation sitting here.

"So the time frame narrows a little bit for me to get to a level that I want to be at."