Danielle Collins has been criticized by some tennis fans on social media for referencing her dispute with Maria Sakkari at the National Bank Canadian Open (Omnium Banque Nationale) in Montreal five days after it happened.

World No. 48 Collins faced eighth seed Sakkari in the Round of 32 at the WTA 1000 event last week, with the American taking a surprise straight-sets victory against the Greek, winning 6-4, 6-2.

However, it was remembered by many for a more unpleasant reason, as an argument broke out between the two players during the match. The dispute occurred in the second set after Sakkari missed her first serve. Collins had already hit the ball back across to her opponent, and Sakkari proceeded to vent her frustration by rage-hitting the ball onto the ground.

The ball bounced back up and into the crowd but didn't hit anyone. Collins asked the umpire if they had seen the incident, to which Sakkari replied:

"It didn't even hit anyone. It was on the ground."

Collins responded by telling Sakkari to 'shut [her] mouth':

"Shut your mouth. Shut your mouth," she said.

Sakkari then asked Collins what her problem was and repeated that the ball hadn't hit anyone as she had aimed it toward the ground.

Five days later, Collins shared some highlights from her time at the Canadian Open, where she reached the quarter-finals, on her Instagram story. However, fans took issue with the fact that she posted a clip of her match against Sakkari accompanied by the song 'Back Off B**ch' by Guns N' Roses.

Some fans have since taken to social media to show their disapproval of the post.

"She's like a 15 year old kid," wrote one Twitter user.

Meanwhile, another asked why the 29-year-old was still 'complaining' about the drama after 5 days.

"She ended up winning the match, and the actual drama was so insignificant, literally nothing deep, was unjustifiedly rude, and still complaining 5 days later... What's iconic here exactly?" they commented.

"Absolutely no reason to call your colleague who did nothing heinous a b**ch," added another.

However, some defended Collins' post, with one Twitter user saying:

"Actions are worse than words, what Sakkari did was awful and the bigger reaction to how Collins responded to it vs. what Sakkari actually did says a lot about priorities."

Collins is now preparing to play at the Western & Southern Cincinnati Open this week, where she will face Anastasia Pavlyuchenkova in the Round of 64.