Nine players are fighting this week for the last two slots at the end-of-season Masters Cup.
Andre Agassi became the sixth player at the weekend to make sure of his place in the eight-strong season's finale starting on November 13 and only one of these six - Andy Roddick - is playing at the Paris Masters.
Agassi joins world number one Roger Federer, Rafael Nadal, Roddick, Lleyton Hewitt and Marat Safin in the Shanghai field.
The final two spots as well as the alternate will be determined this week during the final tournament of the regular ATP season, which started on Monday.
Argentine Guillermo Coria and Russia's Nikolay Davydenko are the front-runners.
Coria needs to win only one match at the high-tech Bercy hall to qualify for Shanghai. The second seed will start the tournament against the winner of the all-Czech first-round match between Jiri Novak and Tomas Berdych.
Davydenko's task is a lot tougher. To qualify without relying on other results, the Russian must reach the final.
If he were to lose earlier Davydenko could be overtaken by one of the other seven players still in the chase.
Those players are Croatian Ivan Ljubicic, Argentines Gaston Gaudio, David Nalbandian and Mariano Puerta, Chilean Fernando Gonzalez, Spain's David Ferrer and Swede Thomas Johansson.
The self-proclaimed biggest indoor tournament in the world, the Paris event has been badly hit by withdrawals.
The only top-five player in the draw is Roddick, the number one seed, who won the Lyon Grand Prix on Sunday.
All 16 seeds have a bye past the first round and will not be in action before Tuesday.
