Watch List: Roger Federer in fight for final spots at ATP World Tour Finals

Roger Federer is in the running for the last qualification spots for the ATP World Tour Finals. (Lintao Zhang/Getty Images) The Watch List spotlights the

Roger Federer is in the running for the last qualification spots for the ATP World Tour Finals. (Lintao Zhang/Getty Images)

The Watch List spotlights the must-know storylines for the upcoming week in tennis. The ATP regular season finishes up at the Paris Indoor Masters, where the final spots for the ATP World Tour Finals will be decided. 

Paris Indoor Masters

[Complete draw]

It's the last regular-season tournament for the ATP, but the final spots for next week's World Tour Finals still haven't been determined.

Here are the storylines to watch this week in Bercy:

Race to London comes down to the wire: Three spots remain for London (Rafael Nadal, Novak Djokovic, David Ferrer, Juan Martin del Potro and Tomas Berdych have already qualified), and it will come down to Roger Federer, Stanislas Wawrinka, Richard Gasquet, Jo-Wilfried Tsonga and Milos Raonic. Federer missed a chance to clinch his berth when he lost to Del Potro in the Swiss Indoors final Sunday. Still, at No. 7, Federer is in the best position to qualify ahead of Wawrinka and Gasquet, who hold the last two qualification spots. Gasquet needs to outperform Tsonga this week to qualify, and the two are slated to meet in the quarterfinals. If both men make it that far, that match will probably determine the last London spot.

Nadal bidding to win record-breaking sixth Masters title of the season: The last time we saw Nadal, he was getting wiped off the court by an incredible offensive display from Del Potro in the semifinals of the Shanghai Masters. The Spaniard subsequently withdrew from the Swiss Indoors, citing fatigue, and he'll be playing the Paris Indoors for the first time since 2009. If there's a court in the world that suits Nadal's game the least, it's the lightning-quick indoor hard courts of Bercy.

"Winning six Masters in one year is a joke," Nadal said after losing at the Shanghai Masters. "It's too much. It's very difficult to do that, no? I already played seven finals. That's much more than what I ever thought. It is something that I never think about. But I am going to go to Paris with motivation to keep playing well, keep enjoying the season."

Djokovic still chasing year-end No. 1: The Serb hasn't lost a match since the U.S. Open and still has a mathematical chance to overtake Nadal to finish the year at No. 1 for the third straight year, though he'll basically need to win out the season and hope Nadal trips up at the last two tournaments. Having lost to Sam Querrey in his opening match last year, Djokovic has an opportunity to pick up points this week and continue the great run of form he had in Asia, where he defeated Nadal on hard courts for the first time this season, at the China Open, and defended his title at the Shanghai Masters.

Sofia Tournament of Champions

Eight women who won WTA International-level tournaments will compete in Sofia, Bulgaria, for points and prize money. Yes, it's kind of a made-up tournament, and yes, two of the players in the field, Ana Ivanovic and Tsvetana Pironkova, actually didn't win a tournament this year to qualify. But with a field that includes Simona Halep, Ivanovic, Maria Kirilenko, Anastasia Pavlyuchenkova, Elena Vesnina and Alize Cornet, there should be some quality matches. The 14th-ranked Halep, who has five titles this year, is the favorite.

Fed Cup final