He added that he also would have surgery on his right ankle so he can start 2019 healthy.
The Serb returned to the number one spot for the first time since 2016 despite his loss in the Paris Masters final against Karan Khachanov.
Spanish tennis star, Rafael Nadal confirmed on Monday that he will miss the ATP finals in London and not play again this season after undergoing an operation on his right ankle in Barcelona.
Boris Becker believes the draw for the ATP Finals gives Roger Federer a big advantage over Novak Djokovic in next week's tournament in London.
Nadal withdrew from the following week's Cincinnati Masters and was then forced to bring a premature end to his US Open semi-final with Juan Martin del Potro due to a knee injury.
"This has been a hard year, a very good one on a tennis level when I have been able to play, but also a very bad one when it comes to injuries.
This way I hope to be in full condition for next season".
We have to go back to Paris 1993 to begin this story, with Goran Ivanisevic beating Michael Chang, Pete Sampras, Stefan Edberg and Andrei Medvedev to grab the second and the last Masters 1000 crown on a fast indoor carpet court.
Djokovic has since gone 43-5, including Grand Slam titles at Wimbledon and the US Open to join Sampras with 14 majors - tied third behind Federer (20) and Nadal (17).
The 32-year-old Spaniard ends 2018 with a 45-4 record and five titles, including an 11th French Open championship in June.
Novak Djokovic of Serbia shouts during the final match of the Paris Masters tennis tournament against Karen Khachanov of Russian Federation at the Bercy Arena in Paris, France, Sunday, Nov. 4, 2018.