Former world number one Andy Murray has joined Novak Djokovic in urging men's tennis governing body ATP to come up with a policy on domestic abuse.
In an interview, former tennis player Sharypova said Zverev was emotionally and physically abusive to her. The U.S. Open runner-up has repeatedly denied the allegations.
In a delayed response to the allegations against the 23-year-old Zverev, the ATP said it condemned "any form of violence or abuse".
Top-ranked Serbian Djokovic, who resigned as ATP's player council chief earlier this year, last week said that the ATP should look to adopt its own policy on domestic abuse, similar to those in American sports, regardless of legal proceedings.
"I don't know how long it was, but it certainly was not immediate," Murray, a three-time Grand Slam winner, said of ATP's response to the Zverev situation. "But I have read some stuff, and obviously tennis doesn't have a domestic abuse policy.
"That is something we as a sport should be looking into, so the ATP know what to do in that situation, rather than having to think and react to it.
"They can be a bit more proactive in a situation like that. They need to take it extremely seriously and see what comes of it in the coming months."