Rafael Nadal could be fit in time to feature in the season-ending ATP World Tour Finals in London after scans showed that his knee injury is not as serious as first feared.

The world number one pulled out of the Paris Masters on Friday due to concerns over the injury, which also caused him to withdraw from the Swiss Indoors Finals last month.

The 31-year-old has had long-standing issues with his knee, but his doctor Angel Ruiz Cotorro talked up the possibility of Nadal being fit in time for the London showpiece.

"It is not a new injury or an injury that has worsened. It's not a different situation than when we came from the Asian tour. All the images of the tests tell us that it is a bit the same, that the tendon is suffering," Cotorro told Spanish newspaper El Espanyol.

"It's a tough year, a season with many games. The tendon is suffering, but the images do not show us anything different either. The first thing was to stop and assess how the knee was, if something new had happened.

"Now we know that there is nothing different, which is a situation that had been dragging on for some time. The problem of tendons in different situations may bother more or less, but we will try to be good to play in London. If he is well, he will play, and if he is not well, he will give up playing. You have to see how it evolves these days."

Andy Murray, Novak Djokovic, Stanislas Wawrinka, Kei Nishikori and Milos Raonic will all miss this year's tournament having featured last season.