ATP Finals 2021: Novak Djokovic says he is "getting better and better every match" ahead of semi-final clash with Alexander Zverev

Novak Djokovic has warned his rivals his tennis is improving with every match ahead of the semifinals of the 2021 ATP Finals. The Serb admitted he is expecting a tough battle against last-four opponent Alexander Zverev, though, and suggested the German may possess the best serve in the game.

Djokovic topped the Green Group in Turin with a perfect 3-0 record after crushing alternate Cameron Norrie 6-2, 6-1 in a dead rubber on Friday night. The World No. 1 broke the Brit five times, did not drop serve and faced just a single break point in the 66-minute masterclass.

The 34-year-old is aiming to tie his great rival Roger Federer's record of six ATP Finals titles with victory at the event's new home. Djokovic won four of his five year-end championship crowns in London from 2012 to 2015, after winning his first in Shanghai in 2008.

Speaking in a post-match on-court interview, Djokovic described the challenge of facing Norrie having already qualified for the last four.

“I tried not to think about the semifinal,” Djokovic said. “It is not easy to walk on the court knowing you have already qualified and you know your opponent. I tried to be professional and I tried to give my best and I played really well."

The Serb also expressed his pleasure at how he navigated his first meeting with the World No. 12, stating he could not be more happy with the state of his game.

"It was the first time we have played each other," Djokovic continued. "I took the time away from Cameron. I analysed his game and knew the game plan and executed it very well. [My tennis] gets better and better every match. I couldn’t be more satisfied with my tennis prior to possibly the two most important matches in the tournament."

Alexander Zverev has "arguably the best serve" in the world: Novak Djokovic

Alexander Zverev and Novak Djokovic after their five-set semifinal at the 2021 US Open

During the interview, Novak Djokovic previewed his semifinal showdown with Alexander Zverev and praised the game of his German rival.

“Sascha is playing well," Djokovic continued. "He is obviously one of the best players in the world, arguably the best serve, it is definitely up there. It is going to be tough. The conditions are quick, so that will be one of the keys, how well will I serve and return.”

Djokovic leads the overall head-to-head series with the World No. 3 by a 7-3 margin, and has won three of their four encounters this year. All four contests were on hard courts, with Djokovic prevailing at the ATP Cup, Australian Open and US Open.

Zverev's lone triumph came in the semifinals of the Tokyo Olympics, where he ended the Serb's Golden Slam hopes.