Patrick Mouratoglou, the coach of Serena Williams, says it was a good decision by Williams not to play the Australian Open.

The 23-time Grand Slam champion had a baby four months ago, and has said she wanted to return to defend her title at the Australian Open. But this week, she announced she would not be playing the event.

"It's never an easy decision to skip a Grand Slam, I guess for any professional, and for sure for Serena...  but it's the best," said Mouratoglou, speaking to ESPN.com. "The thing is, when she gave birth, things didn't go as smooth as she expected. She had some complications—I mean, the baby was perfect, but she had some issues afterwards—and these medical issues delayed the moment that she could come back to practice."

A week ago, Serena traveled to Abu Dhabi and played against 2017 French Open champion Jelena Ostapenko in an exhibition. Williams lost the match.

"She always thinks she can find a way, even when she's not ready, so it's always difficult for me to convince her not to compete," Mouratoglou said. "So I thought it was a good idea for her to play a match and see exactly where she was and see if she felt like going to the Australian Open, and being not prepared the way she usually is.”

Even as a new mother, her coach says she still has the desire to return to winning big titles. Mouratoglou says that she now could return at Indian Wells or Miami.

"Your life changes, but the athlete, the competitor, is the same, exactly the same," Mouratoglou said. “I didn't see any difference. She thinks the same way, she acts the same and for those who were wondering, I can tell that she didn't change, when it comes to business, her tennis— she is exactly the same person.

“I am not worrying at all,” he added. “Whatever happened [on the tour] in her absence, if she comes back, it is to win. Will she come back or not—[time] will tell, but she comes back to win."

Williams will have dropped off the rankings when she returns to the tour, but will be eligible for a protected ranking.