The US Open began on August 28 with beleaguered star Maria Sharapova being the centre of attention with a first appearance at a Grand Slam since her drugs ban.

The Russian ace was up against Simone Halep in the first round of the tournament but was able to outlast her with the scoreline 6-4, 4-6, 6-3.

She continued her surge in the second round clash by beating world number 59, Timea Babos, 7-6 (7-4), 4-6, 4-6.

However, the scheduling of those matches has come under intense criticism from former US Open finalist Caroline Wozniacki, who believes Sharapova has been given preferential treatment over others in the competition.

Sharapova has played both her matches at the Arthur Ashe Stadium and will also do the same in her third round contest against Sofia Kenin on Saturday.

But Wozniacki has described the decision regarding allotment of matches for the Russian counterpart as ‘questionable” given her controversial past.

The 30-year-old is playing her first Grand Slam since returning from a 15-month doping ban and placing her on the main court “doesn’t set a good example” according to Wozniacki.

The fifth seeded star lost to Ekaterina Makarova on Wednesday in the second round on court 17.

“I think putting out a schedule where the number five in the world is on court five, fifth match on, I feel at 11pm, I think that's unacceptable," Wozniacki said, as per BBC Sport.

“When you look on centre court [Ashe], I understand completely the business side of things and everything, but someone who comes back from a drugs sentence and, you know, performance-enhancing drugs, and all of a sudden gets to play every single match on centre court, I believe is a questionable thing to do.

“I think it doesn't set a good example.”

Wozniacki was originally scheduled to play on court five, but rain on Tuesday forced her match to be shifted to court 17.

She added: “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 five.

“Finally they moved us to court 17, which is a really nice court, actually, and we had a great atmosphere out there.

“But, yeah, I think they should sometimes look into what they need to do in the future.”

Sharapova was needed a wildcard to get into the main draw as she is ranked 146th and makes her way back after the lengthy ban.

Her opening match drew almost 24,000 spectators on Monday, which is believed to be the reason the authorities have continued to schedule her matches on the same court.

This is not the first time the duo has been critical of each other. Following the acceptance of the Russian of failing drug tests and during her comeback, Wozniacki has voiced her opinion saying Sharapova was let off easily for her actions.

It remains to be seen if the 2006 US Open champion responds to Wozniacki’s claims as she aims for the highest honour at the Flushing Meadows after being sidelined for over a year.