While the fight for the top place going to the final tournaments of the season, there is also a sub-plot set to unravel with the newly refurbished Bercy Arena set to determine the final eight places for London.
The Swiss 17-time Grand Slam winner won his 82nd career tournament and sixth title at Basel on Sunday, extending his winning streak to 12 matches and record for the year to a Tour best of 66 wins against 10 defeats.
Djokovic has been absent in recent weeks after his wife gave birth to their first child, a boy named Stefan last week, while his lead over Federer has been slashed to fewer than 500 points with 2,500 up for grabs at Paris and the season-ending World Tour Finals in London.
On top of that, the 33-year-old Basel native can also pick up further points when he plays the Davis Cup final for Switzerland against France which begins on November 21 in Lille.
"It would be very special to reclaim number one," said Federer.
"World No. 1 is what it's all about in our game and with the year I have had and the amount of finals I have played, the level of tennis I have played, I am pleased to see that I have a shot.
"But having a shot and being there are two separate things. I am sure that Novak is going to come in very motivated, just after having become a father. I am very happy for him. There are clearly interesting weeks ahead."
World number three Rafael Nadal is out for the season as he gets set to have an appendix operation while Swiss number two Stan Wawrinka is guaranteed his place in London and Croat Marin Cilic, ranked seven, qualifies automatically as US Open champion.
British two-time Grand Slam winner Andy Murray has also hit top form coming to Paris and outlasted Spaniard Tommy Robredo on Sunday, saving five match points on the way to his third win of the season in 3 hours 20 minutes, the longest ATP final of the year.
The victory for the 27-year-old Scot was his 20th match in five weeks, but lifted him into fifth in the race to London, ahead of Japan's Kei Nishikori, Czech Republic's Thomas Berdych and David Ferrer of Spain.
Canada's Milos Raonic, a beaten quarter-finalist against rising Belgian star David Goffin at Basel, and the player Federer defeated in straight sets in the final, needs a strong showing coming in at ten, while Bulgarian Grigor Dimitrov is also in the running, starting the week at number 11.
Federer has had a superb season and will now be looking to get his extended family installed in the French capital as well as recovering from his efforts in Basel where he won a sixth title.
"That's actually the goal for the next day or two," said the father of two sets of twins.
"It's not a small job," said Federer who has won three of his past four tournaments.
"I'm looking forward to Paris, I enjoy playing there," added 2011 winner Federer who lost a year ago to Djokovic in the semifinals.
"I played well last year so let's see how it's gonna go. I play probably on Wednesday (after a bye). I might be a little tired but there's still an opportunity to recover once we get in the city.
"I'm playing with confidence, and it's indoors, not exactly a super-grind.
"I'm in a section of the draw with a lot of big servers," he added, in reference to the presence of Ivo Karlovic and Raonic on his side of the draw.