Martina Hingis just can't help herself sometimes, so after dispensing gracious comments through most of the first week of the Australian Open, she let a few jabs slip about the Williams sisters this afternoon, including calling No. 3 seed Serena "quite heavy."

When asked about Venus Williams's absence at this tournament because of a wrist injury, Hingis replied: "It's not that easy not to be injured. You have to maintain your rhythm and once you start being a professional and playing on tour, you don't have that much time to practice and recover your body.

"So I especially guess Serena is quite heavy, although she lost a lot of weight, I think, since I saw her last time, and Venus is tall, a big girl."

Serena, whose strict workout regimen includes a lot of weight training and muscle-building, is listed in the WTA Tour media guide as being 5 feet 10 and 145 pounds. Venus, the more lanky of the sisters, is listed as 6-1 and 160 pounds. Hingis is listed as 5-7 and 130 pounds.

Hingis also called the Williams sisters "surprise packages," saying "with them sometimes, you don't know what is going to happen."

Still, she did have some kind thoughts for Serena, saying, "I love her dress, though." Serena has been wearing a distinctive red-and-black tennis dress here, along with bright red Puma sneakers.

The Inside Scoop

The retractable roof on Rod Laver Arena has been getting a lot of use over the past few days as the changeable Melbourne weather has produced plenty of scattered showers. Still, while some players are getting near-perfect indoor conditions on the center court, others have had to slug it out under the elements on the outside courts.

On Friday, Tim Henman was shuttled off the court "three-and-a-half" times when rain showers interrupted his 6-1, 6-4, 4-6, 7-6 (8-6) victory over Sebastien Grosjean--once he and Grosjean only made it partway back to the locker room before being called back to the court. Anna Kournikova had to serve into the sun in her win over Kveta Hrdlickova, and Jennifer Capriati had to deal with swirling winds in her 6-4, 6-4 win over qualifier Jing-Qian Yi.

All the while, Mary Pierce, Pete Sampras, Lindsay Davenport and Andre Agassi were playing comfortably at Rod Laver Arena, with the roof closed.

"I think it was a huge advantage to me that the roof was closed," Davenport said after defeating Alina Jidkova, 6-0, 6-1, on Friday night. "It's so much easier to play indoors, so I was lucky to get in one that way and hopefully I'll get used to playing outdoors again tomorrow."

The roof is open at the start of each day, unless it is raining or extremely hot. If the weather does become inclement at any part of the day, it is closed, and play is usually halted on the outdoor courts. When the weather improves again, play resumes outside, but the roof will remain closed if the tournament referee feels bad weather may return later in the day.

"The show courts and Rod Laver Arena play differently than the outside courts no matter what, so we don't see it as giving any players special treatment," tournament spokeswoman Lysette Shaw said. "The good thing about our tournament is that the show goes on. Even if the weather is bad, we will have some matches, and that's good for both the players and the fans."

Australian Open

When: Through Jan. 30.

Where: Melbourne Park, Melbourne, Australia.

TV: ESPN, ESPN2.

Friday's Results: Men--Andre Agassi (1), United States, def. Mariano Zabaleta, Argentina, 6-4, 6-4, 6-2; Pete Sampras (3), United States, def. Wayne Black, Zimbabwe, 6-7 (11-9), 3-6, 6-3, 7-5, 6-3; Tim Henman (11), Britain, def. Sebastien Grosjean, France, 6-1, 6-4, 4-6, 7-6 (8-6); Mark Philippoussis (16), Australia, def. Andrew Ilie, Australia, 6-4, 7-6 (6-4), 6-1.

Women--Lindsay Davenport (2), United States, def. Alina Jidkova, Russia, 6-0, 6-1; Mary Pierce (4), France, def. Miriam Oremans, Netherlands, 6-2, 6-4; Julie Halard-Decugis (9), France, def. Elena Dementieva, Russia, 3-6, 6-4, 6-2; Anna Kournikova (11), Russia, def. Kveta Hrdlickova, Czech Republic, 2-6, 6-3, 6-4.