Roger Federer cast doubt on his participation at the Paris Masters beginning on 30 October following his win against Adrian Mannarino at the Swiss Indoors on Friday (27 October).
The Swiss ace made eighth ATP semi-final of the season and is on course to win his seventh title of the season. Federer is in a race with Rafael Nadal for the year-end number one ranking and can reduce the point's deficit to the top-ranked Spaniard from 1960 to 1460-points with a win in Basel.
The 36-year-old, however, has to win 500 points in Basel and 1000 on offer in Paris to take in a winner takes all shootout at the ATP Finals in London but could hand the advantage back to Nadal, who has confirmed his participation in Paris, if he pulls out of the event.
Federer has been clear from the start that chasing the number one ranking was not his priority as he focused on remaining healthy in order to win in Basel and the ATP Finals in London. He is on course to make it one of his most successful seasons in a decade.
"I'll decide when it's over this weekend what to do with Paris," Federer said after his win over Mannarino, as quoted on Yahoo Sport.
"I'm hoping to play there, but there's also a good possibility that I won't. It depends on how I feel," he added. "We'll see what happens, health is always more important at this stage of my career."
Federer, meanwhile, had a tougher game in the quarter-finals than his first two rounds when he breezed through in straight sets. The Swiss ace had to come from a set down to clinch a place in the last four.
The 19-time men's singles Grand Slam champion will face David Goffin in the semi-finals and could face either Juan Martin del Potro or Marin Cilic in the finals, but that is if he can overcome the Belgian, who beat Jack Sock in his quarter-final clash.