Her record outside the major tournaments has not been as consistently excellent as that of predecessors like Chris Evert, Martina Navratilova and Steffi Graf. Williams has, however, won more Grand Slam singles titles in the Open era than anyone, male or female; she broke Graf’s record in Australia. Williams won her first at the 1999 United States Open when she was just 17, and 18 years later she is just one short of the record of 24 held by Margaret Court, the Australian star whose career spanned the amateur and Open eras.

“The thing that was very, very important for her was to beat this record of Steffi Graf, which she had, by the way, a difficult time doing,” Mouratoglou said. “I know there was a form of decompression after that, which I can perfectly understand. She’s at an age where it’s perfectly understandable that she wants to start a family, and I know she’s had that desire, so it’s a very good thing for her.”

Paradoxically, Williams will return to No. 1 in the WTA rankings on Monday despite not having played a match since her victory in Australia.

It is unclear whether she will play another. She will turn 36 in September but has said that she intends to resume her tennis career. Mouratoglou said she told him the same thing and asked him to remain “on hold” to coach her when she returns.

“I will think that over,” said Mouratoglou, who added that he had no current plans to coach any other leading professional players.

“It lightens my calendar, that’s for sure,” Mouratoglou said of Williams’s hiatus. “But I do lots and lots of things, and it will allow me the time to develop some of my other projects more quickly and more efficiently.”

Meanwhile, he sees it as “opening doors” for those who will play for big titles in Williams’s absence, among them Victoria Azarenka, who plans to return to the tour in July after having given birth to her son, Leo, in December. Maria Sharapova will return from her ban for a doping violation on Wednesday in Stuttgart, Germany.