Novak Djokovic knows the onus is partly on him to prevent Andy Murray climbing to the top of the men's rankings by the end of the year.
Murray is closing in on top spot and could climb above Djokovic with victory at this week's Paris Masters, as long as the current incumbent does not reach the final.
But Djokovic, who has suffered a dip in form since completing a career Grand Slam at the French Open this year, believes he can challenge on his return to Paris.
"I feel good right now," he said. “The last couple of months were not easy.
"Mentally I've had to redefine my goals and things that are happening on and off the court and just make sure that I'm in a good place and that I can perform as well as I expect from myself.
"Everything is clearer and I'm going in the right direction. I'm just focused right now on Paris.
"[Murray] definitely deserves to be in the position to finish up the year as number one.
"Whether or not that's going to happen, it doesn't depend only on him. It depends on me as well."
Discussing being back in the French capital, Djokovic added: "It gives me a lot of great emotions and butterflies in the stomach when I think of the last time I was in Paris and what has happened," he added.
"I'm hoping that I can finish the season as well as I did the last couple of years. I had great records in the indoor season and always enjoyed playing in Paris.
"So we are coming to the finish line, and I really do feel comfortable playing in the indoor events and on this surface."
Top seed Djokovic will face Nicolas Almagro or Gilles Muller in the second round, while Murray awaits the winner of the first-round match between Robin Haase and Fernando Verdasco.