The world No 4 took Nadal to five sets in the US Open final earlier this year, his first appearance in a grand-slam showpiece, and knows how to handle big occasions.
As a outcome, if I manage to get the year-end number one, that would be fantastic.
"But I really hope I will be able to serve every single day a little better, and my hope is to be on Sunday serving normal", he added.
Speaking after his Paris Masters win about his chances of claiming a record-equaling sixth year-end number one finish, Djokovic said: "There's always a chance that I win all my matches in London, that I play well".
"Everything Roger does, he does 100 per cent, so I think he's 100 per cent behind Sascha otherwise he wouldn't sign him".
The Spaniard had been unable to serve because of the injury but said: 'I started yesterday, very slow.
"I am confident that I can be very competitive, but it's a tournament that you will play the top guys since the beginning, so you need to be 100 percent ready", said the 19 Grand Slams victor.More news: Mobile Launching 5G Nationwide on December 6
More news: Vanna White hosts ‘Wheel of Fortune’ as Pat Sajak undergoes emergency surgery
More news: Missing man feared dead after hand, wedding ring found in shark
"What I like about the young guys like Matteo here qualifying for the first time, it goes away from just saying like: 'Oh, we have some talented players on the tour, '" Federer told reporters.
While 19-time Grand Slam champion Nadal has injury worries, few would bet against either him, 20-time Grand Slam champion Roger Federer or Djokovic, victor of 16 majors, lifting the trophy next Sunday.
The Serbian will face Federer for the 49th time in a keenly anticipated group game that will be repeat of the Wimbledon final, which Djokovic won in five sets.
"If I did I would be flying to China after NY because I was in a positive position".
As the eight men gathered for their pre-tournament commitments on Friday, taking a boat ride from the London Eye to the tournament venue at the O2 in south-east London, the youngsters contrasted neatly with the old guard of 38-year-old Federer, 33-year-old Nadal and 32-year-old Djokovic. Zverev recovered from a poor first half of the year to qualify for London, and Berrettini made the semis of the US Open and picked up two titles to become the first Italian to qualify for the season-ending finals since Corrado Barazutti 1978.
He has enjoyed a stunning year, beginning at the Australian Open where he beat Federer on the way to the semi-finals.
"I'm very excited to play against Novak again here, happy to be in his group", said Federer.