The loss was the 20-year-old’s third in a row. It is the first time since 2021 – when he was ranked outside the top 100 – that the Spaniard has endured such a losing streak, according to the ATP.
Alcaraz, who missed last year’s Finals through injury, lost to Grigor Dimitrov in the fourth round of the Shanghai Masters last month and was then stunned by Roman Safiullin in the opening round of the Paris Masters.
Alcaraz will have a chance to make amends in Turin, Italy when he faces Andrey Rublev on Wednesday but needs to win his two remaining group stage matches to have any chance of advancing to the semifinals.
“It’s the only tournament where a loss does not knock you out,” Alcaraz said, per the ATP. “I still have a chance to continue improving and to get through the group stage. Tomorrow I’ll practise to improve everything that I didn’t do well today, which is a lot.
“Even though the court is very fast, I need to be more consistent. At the end of the second set and the start of the third, I hit three or four shots out straight away. That can’t happen, although everyone has their own style.
“I watch Novak, for example, and he doesn’t give anything away straight away. My consistency was really lacking against Zverev.”
Alcaraz hadn’t played since that shock defeat Safiullin on October 31 after being forced to withdraw from an ATP tournament in Basel with foot and back injuries.
The two-time grand slam champion said he’s been “training pretty well” and “feeling good,” but said he wasn’t happy with his “tennis level” after the defeat.
“It’s been a long and demanding year,” he added. “I have to improve to get to this point of the season in better conditions, above all mentally.
“It’s probably mental fatigue. If I want to win this tournament … I have to get to this point of the year relaxed with a desire to win everything that is put in front of me.”
Zverev had struggled for consistency since returning to the circuit after seven months out with an ankle injury sustained at the French Open last year, but the German has started to find some form in the second half of the season, including winning titles in China and Germany.
There were fears Zverev may have suffered another injury after slipping towards the end of the match and then gingerly hobbling between points, but the 26-year-old was confident it isn’t anything serious.
“I didn’t twist my ankle. I kind of slipped,” he said, per the ATP. “There was a pain for a while and I don’t think any damage has been done.
“I hope not and we will see when it settles down. It is nothing comparable to Paris.”
Next up for Zverev is Daniil Medvedev, who beat compatriot Andrey Rublev in straight sets on Monday.