We still don't know exactly how Roger Federer injured his knee, but the result could be significant. There's a chance we may not see him in competition until the French Open.
The larger question: How fit will Federer be for his prime targets of the summer, Wimbledon and the Olympic Games?
Federer underwent arthroscopic knee surgery during the first week of February to repair a torn meniscus in his left knee. As a result, he pulled out of tournaments in Rotterdam and Dubai (his training base, where he has played the ATP event for six consecutive years). His next scheduled event is Indian Wells, which begins on March 7.
In a statement issued shortly after his surgery, Federer expressed confidence that he "will be able to return to the tour soon." However, a projected return at Indian Wells could be overly optimistic, according to prominent sports surgeon Bruno Waespe, who told Swiss newspaper Tages Anzeiger, "If only the meniscus is affected and not the cartilage, the prognosis is good. Then Federer can return in six to eight weeks in the competition mode."
That doesn't bode well for a return any time before the European clay tour. Trouble is, Federer has already decided to skip that segment in its entirety until the grand finale at Roland Garros.
That leaves the world No. 3 in a jam. Or does it?
Federer currently has a substantial lead of 2,470 rankings points on No. 4-ranked Stan Wawrinka. Federer didn't play Rotterdam last year, so any points he would have picked up there in 2016 would have been gravy. However, he is automatically losing the 500 points he earned for winning Dubai last year. If Federer misses the Indian Wells Masters 1000, he'll also be unable to replace the 600 runner-up points he earned. And last year, he accumulated 950 points on the Euroclay circuit that he's skipping.
That's a net loss of 2,050 points.
Yet Federer will probably be in surprisingly good shape even if he doesn't hit a ball in competition until Roland Garros. Wawrinka would be obliged to have a very strong winter/spring (he's defending winner's points in Rotterdam) to trade places with him, and even if that were to happen, so what? For seeding purposes (the only thing that matters for Federer at this point) there's no real difference between Nos. 3 and 4.
Federer's lead over No. 5 Rafael Nadal is nearly 4,000 points, which in previous years at this point in the calendar may not have seemed like an entirely safe lead. It's different now, with Nadal still searching for his A-game. Besides, there just aren't enough points on offer to allow both Wawrinka and Nadal to collect enough points to send Federer down to No. 5, where he could face top-ranked Novak Djokovic before the semifinals of a Grand Slam.
When it comes to this critical year when Federer will likely play his last Olympics Games, he certainly has saved and invested his rankings points wisely.
However, there's also this little matter of the long-term state of the left knee. His 34-year-old joints will have to hold up under punishment on red clay, followed swiftly by grass and then a heavy workload of singles and doubles on the hard courts at the Olympics in Rio during the second week in August.
There's no denying that the 17-time Grand Slam champion is in uncharted territory. He's never gone under the knife before. His most serious injuries previously were back problems that slowed but failed to stop him in 2008 and 2013.
The biggest takeaway from those episodes was how closed-mouth Federer and his highly disciplined camp were about them. And if they chose to play their cards so close to the vest on those occasions, it's a good bet they would be equally if not more reticent regarding this latest setback.
The early details confirm this theory, for we still don't even know for certain when Federer sustained this injury -- or how likely it is to be a recurring or serious threat.
One report described it as a freak injury that occurred on a family outing in a park the day after Federer lost to Djokovic in the Australian Open semifinals, according to Swiss publication Le Matin. The other claim is that Federer was carrying the injury as far back as the Brisbane tune-up tournament, and it grew progressively worse through the Australian Open. After he lost, Federer decided it was time to do something about it.
Federer himself has done nothing to clear up the confusion, which for now probably is a smart, if not very satisfying, play. He knows that keeping people guessing can be an asset, and at this stage of his career, he's going to reach for every advantage he can find.
If this hiatus turns out to be a long one, stretching all the way to the French Open, it may end up feeling like an intermission preparing us for the final, absorbing act of an astonishing career.