If one looks back to this same time last year, Novak Djokovic was building up a head of steam that would eventually propel him to the top of the tennis world in 2011, with one of the most memorable seasons ever.
However, the end of 2011 is absolutely a reverse-image of his amazing end to 2010. He not only is not playing in the Davis Cup final, but also is not playing the kind of tennis we all saw him play throughout 2011.
It really is quite similar to the situation Rafael Nadal went through last year when he was the 3-Slam winner and ran out of steam towards the end of the season with minor injuries and niggles.
His body was unable to handle the continuous wear and tear of the long, gruelling season, and he ended up winning only three titles throughout all of 2011, with only one of those being a Grand Slam.
Now, Djokovic is playing some of his worst tennis of the season.
It's all well and good to try and compete in the big tournaments, but sometimes an athlete's body just ends up rebelling against all the hard work, and needs some proper treatment and rest.
Take the case of Usain Bolt.
The world's fastest man went through a long layoff and came back, maybe not as strong, but good enough to still surpass the rest of the field.
Djokovic's shoulder and back (despite his claims to the contrary), still seem to be problem areas, and his long layoff seems to have affected his ability to run around with the best and retrieve those unretrievable balls that he has become famous for.
If one takes a look at Djokovic's last two losses, the first one to Kei Nishikori in Basel was pretty much down to a recurrence of his shoulder injury. This also caused him to pull out from the Paris Masters. This shoulder injury has been carried forward since the Cincinnati Masters, when he eventually retired in the final against Andy Murray.
Following Cincinnati, his back gave way during the U.S/ Open final, but he still willed himself to win the fourth set in the final against Nadal to close it out, as he started going for more winners to try to close out points early.
They say that hindsight is always 20/20 vision, but all those who said at the time that playing Montreal and Cincinnati back-to-back would result in bodily wear and tear with longer-term repercussions were probably right.
His sheer will to complete a historic season did carry him through the U.S. Open, but having to come back from two sets down against Roger Federer in the semifinal and then having to run around for four hours with Rafael Nadal seemed to be the proverbial "last straws" that broke the Serbian's back (and shoulder).
Since his return, he's been only a shadow (probably not even that) of his 3-Slam and 5-Masters winning self, struggling through his matches. It seems that the dominant Djuggernaut has slipped off the tracks for the moment.
The big question, however, is whether this slip is temporary or something Nadal-like whereby the Spaniard failed to overcome Djokovic in the six finals they have played this year.
Djokovic probably needs a combination of rest and proper treatment of his shoulder and back, otherwise he may go through 2012 with some shock defeats and injury retirements.
This version of Djokovic that is currently playing in London is also depleting that aura of invincibility he had created up until the 2011 U.S. Open, and that could make his rivals more confident when they step onto the court with him.
Djokovic's second loss, to David Ferrer in the round-robin stage at the ATP World Tour Finals, is definitely his worst performance of the year.
He was simply unable to hit easy returns, with Ferrer (one of the weaker servers in the game) managing to win every single one of his first-serve points in the second set.
There is likely to be no sympathy for his plight from countryman Janko Tipsarevic when they meet in the final round-robin stage, as Tipsarevic would definitely want to end his year on a high note.
A humble suggestion to Djokovic would be that following the ATP World Tour Finals, which he currently seems to have minimal chance of winning, he should seek the best possible medical treatment for his back and shoulder. If there is even the slightest niggle, just skip the exhibition tournaments in Abu Dhabi and Perth in December and January, respectively.
Granted that he wouldn't have played any competitive tennis before the 2012 Australian Open, but then again he really didn't do so in 2011 either.
If Djokovic wants to keep his No. 1 ranking, he would do well to manage his schedule around his injuries before they become chronic and he starts seeing his ranking points disappear quicker than Halloween candy.
None of his fans, or even fans of tennis in general, want to see a Nadal-like turnaround by which Djokovic becomes a footnote in 2012 and is unable to compete at his highest level.
He does seem to have age on his side and his game is capable of winning him at least two Grand Slams a year for 2012 and 2013.
But if his body is unable to recover, he may end up repeating his trend of retirements and slip down the ranking order for someone else (could be Federer, Nadal or even Andy Murray) to usurp him as world No. 1 in a few months.
It would be no Djoking matter if he is unable to motivate himself to be better conditioned so he can peak at the right times during the season going forward.