Zverev said he was “sick and tired” of having people accuse him of being aggressive and abusive
An investigation will be carried out into allegations by world number five Alexander Zverev that his girlfriend was treated too violently during a fight with a member of his entourage.
In a statement, the ATP said the matter was being looked into after Zverev said a person was caught on camera punching his partner against a wall.
The ATP said in a statement it had made an “immediate inquiry”.
Zverev’s agent said the 21-year-old has been suffering from a back injury.
“His injuries caused him to withdraw from a doubles match in Hong Kong and, in an attempt to ease these issues, have increased pressure on him to complete his ATP activities,” Tony Godsick said.
Zverev, who has described his girlfriend as a “fighter”, has lost his two singles matches at this week’s Next Gen ATP Finals in Milan.
He said on Friday he wanted to “prove myself wrong and show my true character” and would continue working on a “cracking physique” with the hope of playing the Shanghai Masters next week.
In his statement, the German said: “This horrific incident happens every single day. Every single time.
“It’s no different than if I was hanging out with your family or girlfriend and someone was beaten up.
“No one’s family or girlfriend should be treated this way.”
Alexander Zverev has been a key player for Germany this year and is their highest-ranked player since Michael Becker reached number five in 1990
Zverev, who has won all seven of his matches this week, said he had been “thrown to the wolves” and that he wanted the world to know what he thought.
He added: “What happened has nothing to do with me or with anyone in my team.
“The past year has been one of my toughest in the professional world, and now I am sick and tired of having everyone in my team and in the media accuse me of being aggressive and abusing women.”
In his statement, Zverev said another person had hit his girlfriend during the fight in their shared home in south-west Berlin last week.
‘I want to heal my family’
Zverev, who knocked out John Isner in straight sets on Friday, has been hitting with rival Nick Kyrgios, the world number 14, at the event.
Zverev and Kyrgios are scheduled to play each other in round-robin play on Saturday.
The ATP Cup has been held for the past 10 years. The competition involves 23 of the world’s best young players who compete in different events in one week, in what is thought to be the most competitive series in professional tennis.
Each of the young players is assigned a team manager, team psychologist and a tour physio.
A spokesman for Zverev said he would play in Shanghai if he was fit, although the sprained and strained back injury is thought to be the main reason behind his withdrawal from last week’s doubles competition in Hong Kong.
In a statement, the spokesman said Zverev planned to return to competitive tennis after Christmas.