Two great rivals and friends, Novak Djokovic and Stan Wawrinka, skipped the entire second half of the year due to various injuries. For Djokovic, an elbow issue was the leading cause of his absence. On the other side, Stan Wawrinka's injured knee required surgery which hampered all his plans for the remaining part of the season. Both made their last official appearance during the 2017 Wimbledon Championships. Wawrinka suffered a first-round defeat to Daniil Medvedev while Djokovic survived up until the quarterfinals stages where he was forced to withdraw from the match against Tomas Berdych due to that elbow injury.

To push the similarity one step further, both players have the exhibition event Mubadala World Tennis Championship in Abu Dhabi as a target for their comeback plot.

Novak Djokovic will seek to regain his status

A twelve-time Grand Slam champion, the 30-year-old Serb player saw his reign abruptly ended by Andy Murray in what was a last-minute shift in the closing stages of 2016. Despite showing some good signs during the spring season on clay (a runner-up in Rome) and then on the grass with his first title in Eastbourne, Djokovic saw his ranking going down into a dangerous spiral. Currently ranked seventh in the world, he is likely to step outside the top 10 for the first time since his admission, more than a decade ago.

Stan Wawrinka looking to keep himself relevant

A late bloomer of the ATP circuit, the second best Swiss tennis player managed to step away from Roger Federer's shadow almost four years ago when he earned his first Grand Slam title at the 2014 Australian Open. Many have feared that it was a one-time wonder but Wawrinka backed up that success with two more Majors (2015 French Open and 2016 US Open).

Moreover, he has reached his second French Open final earlier this year only to lose it to Rafael Nadal who has claimed his 10th title at Roland Garros.

Aged 32, Wawrinka is currently ranked ninth in the world but he will step outside the top 10 by the end of the year. Moreover, he will have to handle the ranking points' pressure during the first half of 2018.

His best outcomes of the current season include a semifinal at the Australian Open, a final at Indian Wells and another final at Roland Garros.

With this two low-ranked tennis stars, the perspective is quite intriguing. Other absentees, namely Kei Nishikori, Andy Murray or Milos Raonic are expected to bring back their top game for January 2018. In the meantime, Roger Federer and Rafael Nadal are trying to substitute this apparent void and they have been doing a decent job, to say the least.