LONDON—Alexander Zverev says his confidence is "below zero" following a first-round exit at Wimbledon, also alluding to recent problems with his former agent.
The 22-year-old German fell to Jiri Vesely in his opener on Monday, saying he played poorly because of some personal issues in the two days before the tournament.
"I would say [they were] very rough for me personally. I'm not going to get into details, but I'm just saying. I have to fix that to play well," he said.
Zverev split in the offseason with his agent, Patricio Apey, in what appears to be an acrimonious decision involving several million dollars. While speaking to press in German, Zverev added that the problems did not have anything to do with his team, and spoke more of what appeared to be a reference to his agent's behavior.
"A person I thought was my friend, with whom I worked for years, is doing everything to harm me," he said. "I cannot believe people can be like this. I'm very angry about it."
Zverev also noted the problems, surprisingly, had begun with his title run at the ATP Finals, the biggest of his career.
"Following a success, that's [when] the work begins, and then things come into the open," he said.
He has had an up and down season: he won the title in Geneva, reached the final in Acapulco and advanced to the quarterfinals of the French Open, but otherwise, has rarely won two straight rounds at an event. Zverev is currently No. 5 in the ATP rankings.