Not even one the world’s greatest tennis players can come back swinging right after having a baby.

Serena Williams, who delivered her daughter Alexis Olympia just four months ago, revealed in a recent Snapchat post that she has withdrawn from the upcoming Australian Open.

“After performing in my first match after giving birth I realized that although I am super close I’m not where I personally want to be,” she wrote, referring to a difficult Dec. 30 exhibition match that she lost.

“My coach and team always said ‘Only go to tournaments when you are prepared to go all the way,’” the 23-time Grand Slam winner (for singles) explained, adding that, “Olympia and I look forward to coming back again.”

Working moms thanked the 36-year-old tennis ace for highlighting how difficult it can be to return to the daily grind after having a baby.

Kristin Randazzo, a mother of three in Florida, had to return to working as a retail manager just six weeks after her daughter was born six years ago. She was sleep-deprived, nursing and suffering postpartum depression, so she wasn’t at the top of her game, either.

“My head wasn’t there. I longed to be home with my baby,” Randazzo, 35, told Moneyish. “I cried leaving her when I had to go to work. Physically, I was more tired from taking care of a baby all night. I was also getting over mastitis (painful breast inflammation from clogged milk ducts), so I was just miserable all around.”

Melissa Musen Gerstein, cohost of “The Moms Podcast” and with Denise Albert, returned to working at CNN six weeks after her daughter was born years ago. “I remember missing the top stories of the day because I had to jump out of a news meeting to run upstairs to pump (breastmilk),” she told Moneyish. In fact, her guilt and anxiety about being both the perfect mother and perfect employee made her lose her milk production, so she couldn’t breastfeed for a full year like she wanted. “I had craved being around the newsroom again … but I was miserable,” she said.

Albert experienced something similar while working as an executive producer at David Blaine Productions after her second son was born. “I had two babies at the same time – I was producing a network TV show, and I had my son – and I didn’t want to step away from either of them, but I had a very hard time doing them both well,” she admitted to Moneyish. “I was very stressed and full of anxiety.”

Working moms are one of the fastest growing segments in the U.S. workforce, with about 7 in 10 mothers (71%) with children younger than 18 working in 2012, according to Pew Research, compared with less than half (47%) of them in 1975. And 40% of all households with kids under 18 include “breadwinner moms” who are either the sole or primary income providers for the family, up from just 11% in 1960. About two-thirds of these women bringing home the bacon are single mothers. And that’s largely because the U.S. is the only industrialized nation in the world that doesn’t provide paid maternity leave, so many families can’t afford to let mom recover longer. Canada gives mothers a year off, in comparison.

“We shouldn’t expect women to jump back into the workforce two weeks, three weeks or even six weeks after childbirth,” said Wendy Sachs, a mother of two and author of “Fearless and Free: How Smart Women Pivot and Relaunch their Careers.”

She told Moneyish that when her first son was born 16 years ago, she was a booker for “NBC News” who was hopping on flights to wrangle guests, but had to reset herself after becoming a mom of two sons less than two years apart.

“Yes, you are looking at your watch in the afternoons now because you have to catch the train to get home and relieve the nanny, or you have to pump three or four times a day. Your priorities shift – and that’s OK,” she said. “We shouldn’t ding mothers for that. It doesn’t mean you’re not committed to your job, or that you don’t love the work you do, or that you’re not ambitious anymore. Nothing is permanent. How you feel today can change in six months or 18 months, and you’ll be gunning for that promotion again.”

New mothers just need time to adjust. “When we push ourselves too much at work and at home, the end result is that everyone suffers: not only the mom, but the family and the people in their professional life who are relying on them to be their best,” Meredith Bodgas, editor-in-chief of Working Mother, told Moneyish.

She returned to work at her previous position at just 12 weeks after her first baby was born, which was all the time off she got under the Family Medical Leave Act, and admitted, “I was not at my peak performance. I was extremely sleep-deprived, because my son was waking up several times a night, and I was nursing, so that literally sucks the life out of you,” she said. “I spent a lot of time crying those first few days back, and now I realize that I really could have used another two to four weeks at home.”

So what can you do?

Be upfront with your boss. Bodgas, who is expecting her second child, knows that managers are more amenable to making accommodations when you propose your own solutions – such as coming in earlier if you need to leave by 4:30 p.m. to relieve the nanny. “When the mother is proposing ideas that work for everybody, it takes the pressure off of the manager to come up with a solution,” said Bodgas, “and that makes the manager more likely to do what you’re asking, because you already thought through all of it.” And foster goodwill at your workplace before giving birth by making sure you’re punctual, dependable and putting forth a positive attitude, which will make superiors and colleagues more willing to work with you.

Ease back into it. Williams can’t jump back into tennis competitions yet, and you may also not be ready for 12-hour shifts or back-to-back business trips. Bodgas suggests requesting to return to work part-time to begin with, or working from home one or two days a week at first, before increasing your in-office hours as you get back into the daily grind.

Nix the non-essentials. “Women – and moms especially – try to do everything they possibly can to show how hard they are working, and you need to say ‘no’ sometimes,” said Bodgas. “I said no to a lot of external meetings, because I had to pump three times a day, and I couldn’t go to after-work socials because I leave by 5 to pick up my son from daycare. If it wasn’t something my manager required, and it wasn’t going to help me meet my goals, it wasn’t something I forced myself to do anymore.”

Get help. Radazzo said that some understanding sales associates with kids of their own would lift things for her while she was recovering. “They would watch the sales floor while I did stuff, stayed on top of me to eat and drink, and even remind me when it was time to pump,” she said. And don’t be afraid to delegate work to assistants or associates.

Actually, get any and everybody to help. “You have a mouth – use it,” Lyss Stern, CEO of the Divalysscious Moms lifestyle site and author of “Motherhood is a B-tch,” told Moneyish. The mother of three who delivered two of her kids by emergency C-section perfected delegating each time she was recovering in the hospital. “You don’t have to be a superhero who saves everyone and does everything.” Her assistant picked up the slack planning events with her lifestyle site. Her husband brought in her laptop and watched the other kids.

Bodgas agreed. “Your support system is so key, especially when you’re not a CEO or a professional athlete who can say, ‘I’m not coming in today,’” she said. “Accept help from anyone, and not just childcare. If someone offers to get groceries, say, ‘Yes, thank you, I’ll take 10 tomatoes.’”

Cut yourself some slack. No mom – or person – is perfect, and you should free yourself from trying to do everything 100%. “This whole concept of celebrity mothers on magazine covers that get back in their skinny jeans or run a marathon just three weeks after they have a baby is such a disservice to so many women,” said Sachs. “Serena Williams acknowledged what our culture has been trying to deny: That having a child is physically, emotionally and psychologically taxing.

“That message is a grand slam,” agreed Albert.