Is Murray the first domino to fall of the 'big four'?
IF MONDAY was the last time we see Andy Murray grace a tennis court at the Australian Open, it was a poignant end.
The former world number one and three-time Grand Slam champion hinted prior to Monday's first round exit at the hands of Roberto Bautista Agut this might well be his last season on the ATP tour.
A lingering hip injury has left the scintillating Scot struggling to regain the form and fitness he has become know for.
A noticeably hobbled Murray fought back from two sets to love down to take the number 22 seed to a deciding set. Unfortunately the comeback faltered 6-2 in the fifth, and Murray was consigned to a first round grand slam exit for the first time since 2008.
He will weigh-up in the coming weeks whether more surgery on the troublesome hip will go ahead. Post-match he hinted a positive outcome might mean a return to Melbourne in 2020. But this may also have been his last competitive match.
Regardless of where things fall, Murray's forecast retirement is a harsh reality check to appreciate what we have now, before it is gone.
As someone who has not lived through the bygone eras of professional tennis, I cannot speak to how this most recent era - and Murray - compares to those which have come before.
But speak to those who have, and most agree this past decade or more of professional men's tennis is perhaps the most prolific there has ever been.
When you rattle off names like Federer, Nadal, Djokovic and Murray, you get a sense of why.
The "big four” share 53 grand slam singles titles between them. To put that into perspective, with just four grand slams each year, that equates to 13 years of tennis dominance by four players.
Murray may only share in three of those titles, but that speaks more to the dominance of the other three than to the Scot's ability.
He has been to 11 grand slam finals. In all but his most recent win - the 2016 Wimbledon final against Milos Raonic - Murray has faced either Djokovic or Federer in the decider.
Eight times a bridesmaid - five times in Australia alone - Murray would likely have enjoyed much more success in any previous era.
All this to say, Murray may be the first of the four dominoes to fall. But even if he is, the others may not be too far behind.
Federer is 38 this year, and although we continue to marvel at his unparalleled longevity, Father Time stands still for no one. He too may soon be gone for good.
Nadal (32) and Djokovic (31) may have a number of years left in them, but whether that is at their prime remains to be seen.
No betting man would go against this trio continuing to feature at the pointy end of tournaments, but the odds diminish year on year.
So do not take for granted what we have now. If, like me, you have put off venturing to Melbourne for a few days in January, it might pay to finally take the plunge.
Lest we soon wake up to an ATP tour without four of the greatest players to grace a tennis court.