Andy Murray: Is the end nigh for three-time Grand Slam winner after latest loss?

When does the pride of a champion and the refusal to back down from a challenge do more harm than good? When does it become clear that the massive investment of time, energy and effort is not paying any kind of dividend at all?

These, and many other questions, will once again ring around the echo chamber in Andy Murray's mind as he tries to plot a path towards one last hurrah at Wimbledon this summer. While the rest of us ask ourselves: 'Is it really all worth it any more?'

One thing is clear, as a former world number one and triple Grand Slam winner, Murray has earned the right to call time on his career whenever he likes. He had hinted this would be his last full year on tour, leading one to wonder whether he might want to finally bow out at Wimbledon in 2025, 20 years after his first match on the hallowed turf.

The poor showing at the recent Australian Open, where he exited without so much as winning a set, prompted the five-time Melbourne finalist to suggest he may well not venture down under again.

The meek nature of the loss to Tomas Martin Etcheverry was offset somewhat by the fact the Argentine was 12 years younger and seeded. No disgrace to suffer defeat by a player on the rise through the rankings. Similarly, losing in the first round in Brisbane a couple of weeks earlier was countered by Murray being the only player to take a set from eventual champion Grigor Dimitrov.

The latest loss, from a set up to journeyman Benoit Paire, is far, far harder to rationalise. The Frenchman had not won a match on the main tour for a year and a half and has long since departed the world top 100. He lost the first set 6-2 and still found enough to get past an ailing Murray. There may well have been a physical issue for the Scot but the damage he may be doing to his mind gives cause for greater concern. He says he wants to keep playing while he's enjoying it. Surely the fun stopped many months ago.

The stats tell a story of steady decline. He's yet to win a match in three tournaments this year. He's now gone out in the first round of six of his past seven events. In his past nine matches, Murray - one of the greatest competitors in the modern history of the game - has won just one. At what point does bravely soldiering on start to damage his legacy?

Two Wimbledons, a US Open title, eight other Grand Slam finals and two Olympic gold medals make for quite the portfolio. He was also half the team that helped Dunblane - sorry, Great Britain - win the Davis Cup. As if all of that was not enough, he then won a tournament nine months after having a hip replaced, proving he can defy science as well as belief. To return to the top level of the tour in singles with a metal hip is unprecedented. It borders on the incredible to then win a title and reach two other finals.

Since losing to Daniil Medvedev in the last of those in Doha last year, however, there has been a steady downturn. He has not won more than two matches at any tour-level event since. Murray's world ranking peaked at 36, just short of a seeding at the Slams. He's now about to drop out of the top 50 again.

He's entered three events in February: Marseille, Doha and Dubai. Given the level of his recent performances, he is surely now questioning whether all that time away from the family is really worth it.

Safeguarding his own mental health must surely come into play alongside preserving his reputation. If he never hits another ball, his status as a great of the game, and a legend of British sport, is already secure.

He has often compared the gladiatorial nature of tennis to boxing. The question is, how many more punches should Murray allow himself to take before hanging up the gloves on a glittering career?