"I think putting out a schedule where the No. 5 in the world in playing on Court 5, fifth match on after 11 [p.m.], I think that is unacceptable," Wozniacki told reporters after losing her Round of 64 match Wednesday to Ekaterina Makarova.
"When you look at center court, I understand completely the business side of things and everything, but someone who comes back from a drug sentence, and you know, performance enhancing drugs, and then all of the sudden gets to play every single match on center court, I think that's a questionable thing to do."
Video: Caroline Wozniacki unhappy with US Open scheduling— CaroWozniackiNews (@CWTennis) August 31, 2017
Video credit: Ekstrabladet.dk pic.twitter.com/5r1JEjCuEj
Sharapova responded Friday, after beating Sofia Kenin 7-5, 6-2.
"With regards to scheduling, as you know, I don't make the schedule," Sharapova told reporters.
"I'm a pretty big competitor. If you put me out in the parking lot of Queens in New York City, I'm happy to play there. That's not what matters to me. All that matters to me is I'm in the fourth round. Yeah, I'm not sure where she is."
Sharapova, who was suspended for 15 months for using meldonium and is playing in her first Grand Slam tournament since the ban, is in the U.S. Open by way of wildcard.
On Sunday it was Patrick Mouratoglou's turn to chime in. Williams' coach said that Sharapova shouldn't have gotten a wildcard to come back.
"When Maria enters a tournament, the best news possible for her is if Serena is not in the draw,'' Mouratoglou told the New York Post. "She's a better tennis player. She's the best of all time. She hasn't been dominating just Sharapova."
Sharapova is ranked No. 146 in the world. She was rejected earlier this year to play in the French Open.
"It would be a great message the tennis world sent to the fans,'' Mouratoglou said. "Whoever is tested positive, whether superstar or not, it's the same treatment. They should vote in a rule someone who comes back from a ban from doping shouldn't get a wildcard coming back."
Sharapova faces Latvian Anastasija Sevastova at 1 p.m. Sunday in the Round of 16 at Arthur Ashe Stadium. Americans Venus Williams and Sloane Stephens are also in the Round of 16.