OPINION: Injuries have put significant question marks over the careers of two of the all-time greats of the game in the wake of this month's Australian Open.
Twelve-time Grand Slam singles winner Novak Djokovic suffered further issues with his troublesome elbow in Melbourne, while Rafael Nadal was forced to retire hurt during his quarter-final contest.
But it’s not so much their latest aliments, more the repetition of injuries and the lack of recovery each time that's taking its toll.
For Djokovic, still just 30 years of age, it’s been a troubling 18 months. For the first half of 2016 he was almost unbeatable, but then off-court dramas, injuries, unusual defeats and more injuries put paid to his Grand Slam aspirations.
There's now the chance the Serbian will need an extended lay-off from the game if he's ever to come back fully recuperated.
Will he find it too difficult to come back to the high level he once was? That’s the big question. A player of Djokovic's standing will not take to the court if he thinks he’ll play below the level he used to.
Before Maria Sharapova had a major injury she was at least competitive with Serena Williams, and at times winning Grand Slam titles. However, when she returned she was never the same player and despite making the top 10 again, was never quite the same contender.
For Nadal, the injuries must surely be catching up with him. He’s stated that this latest case with his right leg will see him back on court in around three weeks, but considering the energy and effort he puts in to every shot it’s little wonder he struggles at times.
The pain that Nadal and Djokovic go through each day must be telling on them and, in turn, gives their opponents more hope of victory.
The big question is, how long can a fit and healthy body be bludgeoned on a tennis court? Roger Federer seems to do fairly well with his limited schedule and he has come back arguably even better than he was prior to injury.
Is that the new model for how to rehabilitate? Both men would do well to sit up and take notice.
Dave Worsley is a contributor for Newshub Sport and Radio LIVE and is in Melbourne covering the Australian Open.