World No. 8 Matteo Berrettini admits he wasn't happy with how he felt physically at the Nitto ATP Finals and his goal for this was to improve his fitness. Berrettini, 24, enjoyed a breakthrough season on the Tour last year and earner a chance to make his debut at The O2 Arena.
The Italian made three ATP finals last year and ended up winning it all in Budapest and Stuttgart. The 24-year-old also made his maiden Grand Slam semifinal at the US Open. In his debut at the Nitto ATP Finals, Berrettini lost to Novak Djokovic and Roger Federer before he beat Dominic Thiem.
"In London, all the players were physically better than me. At the end of the tournament, I told my team that I wanted to improve this for next year." Berrettini said, per We Love Tennis France. "Today I am still in contact with my physical trainer, who is now with his family in Italy, and also with my trainer.
I care about my weight, but it's not my priority right now. I work very hard. "My knee injury in 2016 gave me seven months to work my body, so I can handle this type of period. However, this situation is much more difficult. My mentality is to use this time to improve, but also to return as quickly as possible. "Now I know I am ready, and therefore it is quite frustrating to see that the circuit cannot resume."