Maria Sharapova returns a shot against Timea Babos at the US Open. Photo: Adam Hunger, AP

NEW YORK – Caroline Wozniacki slammed as “unacceptable and questionable” the US Open decision to give Maria Sharapova back-to-back matches on the showpiece Arthur Ashe Stadium in the Russian’s first Grand Slam appearance since serving a doping ban.

Wozniacki was furious that she was sent to play her second-round match on an outside court, while five-time major winner Sharapova was scheduled twice on the tournament’s biggest arena.

“I think putting out a schedule where the fifth seed is playing on Court 5, fifth match on after 11pm – I think that’s unacceptable,” said Wozniacki who, like Sharapova, is a former world number one, but who has never won a Grand Slam title.

“When you look on Center Court, I understand completely the business side of things, but someone who comes back from a drugs sentence – performance-enhancing drugs – and all of a sudden gets to play every single match on Center Court, I think that’s a questionable thing to do.

“I think it doesn’t set a good example, and I think someone who has fought their way back from injury and is five in the world deserves to play on a bigger court than Court 5.

“Finally they moved us to Court 17, which is a really nice court actually and we had great atmosphere out there, but I think they should probably look into what they need to do in the future.”

Caroline Wozniacki reacts after winning a point against Ekaterina Makarova. Photo: Julio Cortez, AP

Wozniacki, the 2009 and 2014 runner-up in New York, became the fourth top-10 woman to exit the US Open on Wednesday night when she lost 6-2 6-7(5) 6-1 to Russia’s Ekaterina Makarova.

Sharapova, the US Open champion in 2006, had earlier seen off Hungary’s Timea Babos on the 24 000-capacity Ashe, two days after she had knocked out world number two Simona Halep on the same court.

Sharapova served a 15-month suspension for failing a drugs test at the 2016 Australian Open, and only returned to the tour in April.

She was refused a wild card to play at the French Open because of her suspension, while injury ruled her out of Wimbledon.

The US Open, however, awarded a wild card into the tournament, the season’s final Grand Slam.