He withdrew from the Monte Carlo Masters with a right-knee injury in April and missed most of the clay-court season, including the French Open.
Djokovic extended his winning streak to 20 straight matches and equalled a personal record of 29 consecutive completed sets won as he maintained the remarkable spell of form that has seen him rise from number 22 in June to the top of the game again.
"The doctor says that is recommended to not play, because if I continue the abdominal maybe can break and can be a major thing".
"Hopefully I can travel with him a bit more next year, and for sure we're going to try to spend a lot more time together in the upcoming weekends and months".
Djokovic will replace Rafael Nadal as the world's top player on Monday after a two-year absence.
Serbia's Novak Djokovic celebrates after winning his men's singles second round match against Portugal's Joao Sousa, on day two of the ATP World Tour Masters 1000 - Rolex Paris Masters - indoor tennis tournament at The AccorHotels Arena in Paris, on October 30, 2018.
It also left Paris ticketholders feeling frustrated after Roger Federer's later match with Milos Raonic was called off after Canadian Raonic also pulled out injured. "I went and I did an ultrasound and MRI, and they found some kind of a lesion in the tricep". "It was unbelievable. I never expected that something like that can happen", he said.
"I would love to be in London, of course", said the Spaniard.
It is huge news for Djokovic, who as recently as the Australian Open earlier in the year was not sure if he would ever truly recover from his persistent elbow injury.
Ninth seed Barty broke Garcia once in each set to win the round-robin tie 6-3, 6-4 in one hour and 16 minutes.
Federer is chasing a 100th career title, while Djokovic is looking to win the Paris Masters for a record-extending fifth time.
Federer, 37, who captured his 99th trophy on home ground in Basel last week, will face either Kevin Anderson of South Africa or Japan's Kei Nishikori on Friday for a place in the semi-finals in the French capital.
Sixth-seeded Dominic Thiem won 6-4, 6-2 against Gilles Simon, beating the Frenchman for the eighth time in 10 meetings.