Roger Federer pulled out of the Paris Masters on Sunday to rest for the ATP World Tour Finals in London.
The indoor Paris tournament starts Monday. The top-ranked Swiss announced his withdrawal after losing a 2-hour, 44-minute final against Juan Martin del Potro at the Swiss Indoors.
"It's the only right decision for me," he said. "I had some niggling stuff and I didn't want to take a chance obviously before the World Tour Finals. I need some time to prepare."
In 2011, Federer won the Paris tournament for the first time at age 30 and took the London title the following week.
"I had one of the best weeks of my life last year," he said. "The fans were amazing, and the last thing I want to do is mislead any fans. This is really just a last-minute decision."
Federer will start a record 302nd week ranked No. 1 on Monday, but risks losing that status to Novak Djokovic in the final two weeks of the season.
Tournament organizers said Federer will be replaced in the main draw by lucky loser Victor Hanescu of Romania.