Caroline Wozniacki unhappy with Maria Sharapova gets prime-time billing at US Open

The US Open broke ranks with the other grand slams by awarding Sharapova a wild card and the five-time grand slam champion has played both her matches on Arthur Ashe Stadium, the biggest arena in tennis.

After beating Simona Halep in the night session on Monday, Sharapova defeated Timea Babos on Wednesday to reach the third round.

Wozniacki found herself scheduled fifth on Court 5, one of the smaller courts at Flushing Meadows, with her match against Ekaterina Makarova eventually moved to Court 17.

The pair were the final players out on court and Makarova finally completed her 6-2 6-7 (5/7) 6-1 victory after midnight.

Wozniacki told Ekstrabladet TV: "I think putting out a schedule where the number five in the world is on Court 5, fifth match on, I feel at 11pm, I think that's unacceptable.

"When you look on centre court, I understand completely the business side of things and everything, but someone who comes back from a drugs sentence and 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.

"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 a great atmosphere out there. But I think they should sometimes look into what they need to do in the future."

It is not the first time Wozniacki has spoken out against the welcome mat laid out for Sharapova since her comeback from a 15-month ban for taking the cardiac drug meldonium.

Wozniacki, who saw her hopes of reaching world number one a week on Monday ended by her defeat, called the decision to award Sharapova a wild card for her first event in Stuttgart in April "disrespectful."

Sharapova's agent Max Eisenbud responded by branding former world number one Wozniacki a "journeyman player", with the Dane later rejecting Eisenbud's apology.

While some players continue to question Sharapova, the Russian has received strong crowd support in both her matches, with the stands packed.

She said: "I think with the way that I played Monday night, I don't think there are any more questions.

"I've had an amazing reaction from fans since I've been back, and that's been very special. I felt it while I was away. I felt it in a real presence since I've been back. It's a very special feeling."

The way Sharapova played against second seed Halep led some pundits to rate her as a potential title challenger.

She was less impressive against Babos but is in a very open section of the draw, with young American Sofia Kenin her next opponent.

Sharapova, the US Open champion in 2006, said: "I certainly have expectations just because I know I've been in these stages before and I've been able to execute.

"There's a certain level of 'I know I can do this, I've done it before. I want to have that feeling again. But there's also the realistic understanding of, 'okay, you haven't been in this situation for a while. It's going to take a little time'.

"Of course, managing expectations is part of it, learning as you play the matches, which is something I haven't done for a long time."