Roger Federer will defend his title when he heads the field at the last event of the ATP Tour regular season, the Paris Masters, starting tomorrow.
The Swiss world No 1 stormed to victory at the Bercy Arena a year ago and will arrive after playing in the final of the Swiss Open against Juan Martin Del Potro.
Federer is focusing on another end of season sprint, but one without a pause as the eight-man World Tour Finals begin in London a day after the Paris final.
That scheduling wrinkle may come back to haunt the ATP as the organisation shortens the 2012 season by a fortnight, eliminating the rest and preparation week before the round-robin end-of-season classic.
With Nadal missing after ending his campaign early due to the knee injury which has kept him off court since June, Federer leads a pack trailed by second seed Novak Djokovic and US Open winner Andy Murray. Djokovic beat Murray for the Shanghai title this month, with neither man playing since.
Murray withdrew from the Swiss Indoors, claiming a back niggle, to the dismay of organisers faced with his second pullout in as many years.
Federer is trying to avoid pressure as the race to the year-end No 1 ranking goes down to the wire with Djokovic pushing hard and results in Paris a key to any possible movement in the table.
"I have to think day by day. It's simple, it's pretty routine, but it's my only way to handle these next couple of crazy weeks," said the Swiss.
"I want to play well at the World Tour Finals, there's no question about that. It's the highlight of the end of the season and one of the biggest events we have in the sport."
Spain's David Ferrer takes the fourth seeding ahead of Czech Tomas Berdych, and a trio of players attempting to clinch berths for London next - France's Jo-Wilfried Tsonga, del Potro and Serb Janko Tipsarevic. Spaniard Nicolas Almagro and France's Richard Gasquet hope to gain the last two spots.