An Australian newspaper is under fire for a cartoon depicting Serena Williams at the U.S. Open

Serena Williams fans across the internet are coming to the athlete’s defense in response to a recently published cartoon from Australia’s Herald Sun newspaper which many are calling racist.

On Monday, Herald Sun artist Mark Knight tweeted a drawing showing an exaggerated caricature of Williams stomping on her tennis racket with a pacifier near her feet — which many felt was comparable to the stereotypes seen in anti-black political cartoons from the Jim Crow-era of America.

The cartoon was an insulting interpretation of Williams’ visible frustration during her highly-anticipated U.S. Open match against Osaka, which she lost after getting into a verbal altercation with umpire Carlos Ramos, who the 23-time Grand Slam champion called “a thief.”

In the background of Knight’s cartoon, an umpire is seen asking Williams’ opponent to let the star win. It isn’t clear whether the drawing of the white and blonde player is meant to represent Osaka, who is the daughter of a Haitian father and a Japanese mother.

After the match on Saturday, Williams, 36, said she believes male players are often given much more leniency in what they can say to umpires, which sparked a conversation about sexism in the sport.

Serena Williams argues with umpire Carlos Ramos

Many on social media were quick to raise serious and critical questions about Knight’s cartoon.

“Well done on reducing one of the greatest sportswomen alive to racist and sexist tropes,” Harry Potter author J.K. Rowling tweeted, “and turning a second great sportswoman into a faceless prop.”

ESPN commentator Jemele Hill called the drawing, “about as subtle as Fran Drescher’s voice.”

Knight defended himself by tweeting out another recent cartoon he’d drawn of male Australian player, Nick Kyrgios.

“Here’s a cartoon I drew a few days before when Australian male tennis player Kyrgios at the US Open was behaving badly,” Knight tweeted, along with the cartoon. “Don’t bring gender into it when it’s all about behaviour. I’ll accept your apology in writing.”

But many users felt that the cartoon, in fact, supported the idea that male players are treated differently than women. It depicts a male official bending over to speak to a defiant Kyrgios, who is then dragged by the ear by a female official in the next frame. Knight titled the panel, “What should have happened.”

In fact, the Kyrgios cartoon ignited further commentary from Knight’s Twitter critics.

“Is there a reason why you exaggerated Serena’s look to be more stereotypical of how black woman have historically been seen by whites,” Twitter user Keisha Lambright responded. “Even taking out gender this is extremely offensive and inaccurate.”

Following her controversial loss, Williams was fined $17,000 from her $1.85 million prize money for three violations: $10,000 for verbally abusing the umpire, $4,000 for receiving a warning about coaching; and $3,000 for breaking a racket. Tennis great Billie Jean King said she believed gender and race ultimately played a role in how the game transpired.

Serena Williams
| Credit: Juergen Hasenkopf/BPI/REX/Shutterstock

“Women are treated differently in most arenas of life,” wrote King in the Washington Post on Sunday. “This is especially true for women of color. And what played out on the court yesterday happens far too often. It happens in sports, in the office and in public service. Ultimately, a woman was penalized for standing up for herself. A woman faced down sexism, and the match went on.”

As of late Monday morning, Knight had not removed the cartoon from his Twitter account or offered an apology.

A rep for Williams did not immediately respond to PEOPLE’s request for comment. The Herald Sun also did not immediately respond to PEOPLE’s request for comment.