Australian Open

Del Potro continues comeback in Sydney

Sydney -- Juan Martin del Potro, who played in just three tournaments in 2010 because of injury, has entered an Australian Open tune-up event as part of his comeback.

Del Potro, 22, won the 2009 U.S. Open title and was ranked as high as No. 4 in the world before a right wrist injury curtailed his play. He made it to the Round of 16 at the Australia Open but played in only two other tournaments since, losing in the first round each time.

The lack of play caused his world ranking to fall to No. 257.

Tournament officials have extended del Potro a wild-card invitation to the Sydney Invitational, which takes place the week before the 2011 Australian Open. That tournament begins Jan. 17.

Copyright 2010 United Press International, Inc. (UPI).

Serena Williams to miss Australian Open

Melbourne -- Australian Open officials announced Thursday that five-time champion Serena Williams had withdrawn from the first major tennis event of 2011.

Williams told tournament director Craig Tiley she had not fully recovered from foot surgery this summer. She has not competed since winning the title at Wimbledon in July.

"Serena is a great champion and we will miss her in January," Tiley said in announcing the withdrawal. "We send her our very best wishes for a speedy recovery."

Williams has reached the finals of the Australian Open five times and has won every one of them. She won the last two Australian titles as well as
in 2003, 2005 and 2007.

Andy Roddick to miss Davis Cup this year

Brisbane, Australia, January 8 -- Andy Roddick will not be a part of the U.S. Davis Cup team this year. The American has pulled out of the tournament to avoid any serious damage to his previously injured knee.