NEW YORK—Samantha Stosur has criticized player facilities provided at the U.S. Open and said that Serena Williams took her practice court on Wednesday.

The 2011 U.S. Open champion said she was not provided with a transport car at her requested time, suggesting that six-time champion and No. 1 Williams likely had better access to transportation.

"I'd say so," said Stosur. "She kicked me off my practice court yesterday, too."

Williams was seen practicing following her second-round win on Wednesday; it is relatively unusual for players to train once they have already played a match that day. It is not known whether the court she used was originally scheduled for Stosur.

Stosur said that she had not been given a transport car before 10 a.m. because she did not have a match that day, and that her practice was also moved.

"I had 45 minutes yesterday. I went on three different courts, so not ideal," she said. "There is obviously 200-something players, here, all wanting to practice and doing everything they need to do.

"You can only do what you can do. But, yeah, it would be nice to have 45 minutes without interruption."

Stosur, who still won her second-round match over Evgeniya Rodina, 6-1, 6-1, said she was making a general comment.

"I'm not trying to make a big deal of," she said. "There are many players in the same boat.

"It's a Grand Slam. It's one of the biggest tournaments in the world. You've got to be able to provide transport to players when they need it."

Stosur plays Sara Errani in the next round.