Was he fit enough to take to Centre Court in his Wimbledon opener? Should he have warmed up for the All England Club at another grass tournament? Why didn't he? Whose decision was it to jump straight into action in SW19 following the conclusion of the clay-court season? What are the implications of this latest set-back for his future on grass?
Twice champion Rafael Nadal's stunning straight-set defeat to unheralded Steve Darcis on the first day of the 2013 Wimbledon Championships raised as many questions in the immediate aftermath of the match as it did eyebrows during it.
At the same time, those eyebrows were sent soaring skywards, jaws on Centre Court dropped in the opposite direction as Nadal was bumped out of Wimbledon early for the second time in two years, following his equally shocking defeat at the hands of Lukas Rosol 12 months ago.
How could this happen? Surely not even the most fervent Rafa sceptic could have seen this one coming? Having steamrollered pretty much everyone before him since returning from injury, reaching nine finals and picking up seven titles including yet another French Open, the old, all-conquering Rafa was back, as strong and as dominant as ever. Wasn't he?
Well, in a word, no. Grass is entirely a different surface to clay and, worryingly, his injury problems seem to have been temporarily shelved and glossed over, rather than solved long-term.
Typically, after the match Rafa refused to blame the result on any physical issues, instead insisting that focus should be directed towards his opponent Darcis, who played brilliantly. That's why we love Rafa: he is a great champion, but even in defeat his many admirable qualities continue to shine through.
Another reason we love Rafa is his warrior spirit. His never-say-die attitude over the years has made him one of the most compelling players ever to grace the courts and we have been privileged to witness some of the greatest matches in the history of the sport because of that - not least that final at Wimbledon, back in 2008.
While Nadal should rightly be lauded for possessing such a quality, there is however a limit to its worth, and when it apparently overrides common sense, questions could, and should, be asked.
The real state of Rafa's fitness will come out in the wash over the coming days and weeks, but despite the immediate denials, his physical condition was certainly a factor against Darcis. It would be madness to suggest otherwise.
Clearly Rafa was not up to doing himself justice, by his own high standards, on grass, a surface which puts different physical demands on a player's body compared to others; the knees in particular are more susceptible to stress on a lawn, such is a player's continual change of direction, slipping and sliding.
His recent results on the red dirt have suggested utter domination, but there have been chinks in his armour and on a number of occasions his fitness, even on a surface well-suited to him and his body, has come under scrutiny. Hindsight is indeed a wonderful thing, but it's difficult to imagine that Rafa's camp had no prior inkling that he was not ready to compete in a grass-court Grand Slam.
Of course Rafa would have been desperate to play at Wimbledon, not only to ride the wave of his recent good form but also to atone for last year's showing. But if a warrior spirit, a desire to compete at all costs, is allowed to go unchecked, for all its potency as a weapon it can be equally self-destructive. And what his participation this time around has only succeeded in doing is compounding that loss, rather than providing some kind of redemption.
There could be physical effects too, although there is little use in speculating on how serious they may be just yet. There is no suggestion that this latest set-back will result in a similarly lengthy time off the court - he missed the remainder of the season following last year's defeat to Rosol - but regardless, the wisdom in sending him out at this year's tournament is one of the most critical of a raft of questions that have been thrown up.
It is now up to Nadal himself to provide answers, both on and off the court.
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