Roger Federer
Federer was expected to return from injury layoff at IPTL Reuters

Tennis stars Roger Federer and Serena Williams will not feature in the remaining legs of International Premier Tennis League, with the tennis action resuming in Singapore on Tuesday after the Japan leg, which ended on 4 December.

Serena, who missed the WTA Finals last month in Singapore due to a shoulder injury, had signed up with defending champions Singapore Slammers for the 2016 season. However, it has now emerged that the former world number, who has won 22 grand slam titles, will not travel to the Southeast Asian country for the second leg of the tournament.

Meanwhile, Federer, who signed up late as the icon player for the 2014 edition winners, Indian Aces, will also not be part of both the Singapore and India legs of the tournament. Notably, the ongoing edition of the tournament has taken a hit after top stars including Andy Murray, Novak Djokovic and Rafael Nadal opted out of the competition.

Unlike the previous editions, which were five-legged affairs, 2016 season has been scheduled to take place only in three - Japan, Singapore and India. Dubai and Manila, the other two venues in the previous season, were removed as hosts and also Philippine Mavericks were not part of the ongoing season.

Nonetheless, IPTL 2016 garnered a lot of attention as both Federer and Serena, who have suffered a long layoff due to injury, were expected to make their return at the exhibition event before the start of 2017 season. However, veteran Indian tennis star and Managing Director of IPTL, Mahesh Bhupathi, revealed that financial reasons were behind the organisers' inability to rope in the top two stars for the ongoing season.

"We have had challenges this year, and we were hoping to get past them. With the current economic climate in India and the uncertainty of spending money, I reached out to both Roger and Serena to explain the situation. They have been both been very supportive of the IPTL the first two seasons and we look forward to bring them in future years," Bhupathi said, as quoted by The Times of India.

Federer's agent Tony Godsick has also reportedly confirmed that the Swiss star withdrew due to "some problems and uncertainties surrounding the IPTL". He added that Federer "hopes to play in future years if the IPTL continues".

Despite not having Federer, the Aces have had a good start to the tournament winning two of their three matches in Japan. On the other hand, Singapore struggled in the first leg and are placed third in the standings.

Ticket sales for the last leg and the final in India are also not encouraging as the Indian government recently demonetised high-value currency notes in an effort to issues due to unaccounted money, according to ESPN. Whether or not the star-studded tournament is able to survive and come up with an edition next year remains to be seen.