Roger Federer is on the verge of becoming the highest prize earner in tennis once again should he win at least one of the next three events he takes part in.
Former world number one Novak Djokovic is the current leader after he overtook Federer in June 2016 to become the first tennis player to reach $100m (£76m) in career earnings.
However, the Serbian has not had the best year in 2017. He last featured in July as he is taking time off to recover from injury to return for the 2018 Australian Open.
Federer, on the other hand, has had a career resurgence in the calendar year, winning six titles including the Australian Open and a record eighth Wimbledon title.
The 19-time Grand Slam champion, currently ranked number two in the world, is now within touching distance of Djokovic in career earnings and will overtake him should he win the Basel Open for the eighth time.
With €395,850 (£352,207, $464,589) on offer for the winner in his hometown event, Federer could also become the first tennis player to reach $110m (£83m) in career earnings.
Should he not win in Basel, however, the Swiss ace can also achieve the feat by winning the Rolex Paris Masters, which takes place on 30 October, with the winner receiving €853,430 (£759,117, $1,003,420), reports Forbes.
Meanwhile, the ATP Finals in London in November have reserved a total of up to $2m (£1.5m) for the winner, should the eventual champion win all his round robin games.
|1. Novak Djokovic||$109,805,403|
|2. Roger Federer||$109,387,410|
|3. Rafael Nadal||$91,199,322|
|4. Andy Murray||$60,807,644|
|5. Pete Sampras||$43,280,489|
|6. Andre Agassi||$31,152,975|
|7. David Ferrer||$30,760,436|
|8. Stan Wawrinka||$30,623,544|
|9. Tomas Berdych||$28,220,153|
|10. Boris Becker||$25,080,956|
The Basel Open began on 23 October with Federer taking part on Tuesday (24 October) in his round-of-32 match with Frances Tiafoe.