'What a joke': Player cops brutal $10k fine over bag at US Open

American tennis player Reilly Opelka has fired a cheeky shot at US Open organisers after he was fined $10,000 for taking to the court with an 'unapproved' tote bag.

The 24-year-old world No.24 had moved through to the third round of the US Open thanks to a straight sets victory over Lorenzo Musetti last Thursday when he got some unwanted news.

CRUCIAL: Ash Barty move that could help save Naomi Osaka's tennis career

SAD: Novak Djokovic's confession about wife at US Open

Unfortunately for Opelka, his choice of bag for that match has cost him a $10,000 fine from tournament officials who deemed the logo on the bag too large.

Opelka, who also reached the third round at this year's French Open, had fun with the decision, tweeting that U.S. Open ticket sales must be struggling this year but at least the pink bag "looked fly."

"US Open ticket sales must be strugglin this year! 10k for a pink bag, at least it looked fly," Opelka wrote.

It seems he was able to take the fine in stride though, progressing to the fourth round on the back of an impressive 7-6 (7-5), 6-3, 6-4 win over Nikoloz Basilashvili.

It marked the first time the 22nd seed had progressed to the fourth round of a grand slam.

Opelka later blasted officials for the fine following the win over Basilashvili, saying it shouldn't be his job to carefully measure every logo on every bag he uses.

"My job is to win matches. I have bigger things to worry about," Opelka said.

"For the referee to tell me it's my job to measure a logo, no, clearly not. It's his job. I'm trying to beat (Nikoloz) Basilashvili and make the round of 16 of a Grand Slam."

Reilly Opelka unhappy with US Open officials over 10k bag fine

Opelka said a mix-up between two different bags had inadvertently lead to the $10k fine.

"The head referee was telling me you should have come in and had this thing measured," he said.

"The ref just told me — I mean, I actually thought it was a different bag. We had that logo specifically made. We measured. It is too big. It was not the same bag I was using at the French Open.

"We made the effort to make it smaller. There was a mistake in production, I think, because in Europe with the conversion, with what was allowed."

The frustrated American said he failed to see the point of fining players for such a minor transgression, adding that it felt out of place among other rules governing the behaviour of players on court.

He said the strict requirements for logo size were at odds with scenes of players breaking racquets and other bad behaviour going unpunished.

"I snapped a racquet over my knee (once), didn't get fined a dollar," Opelka added.

"And you bring a pink bag and got fined 10 grand? What a joke."

Opelka is one of three American men to have reached the Round of 16 in New York this year, along with Frances Tiafoe and Jenson Brooksby.

He will meet South African Lloyd Harris on Monday with a quarterfinal berth on the line.

With Reuters

Click here to sign up to our newsletter for all the latest and breaking stories from Australia and around the world.