Clijsters postpones comeback because of knee injury

   International Tennis Hall of Famer Kim Clijsters has postponed her comeback because of a knee injury.
   "I've had to make the decision that I will not be able to compete in January," the 36-year-old mother of three tweeted Monday. "I am undergoing rehab and treatment for a knee injury. It's a setback but I'm determined as ever to get back to the game I love. I really appreciate all your support and encouragement."
   Clijsters did not disclose the nature of the injury, how it occurred or when she hopes to return. She reportedly was hurt while playing padel, a different racket sport.
   Clijsters, who left the circuit for the second time in 2012, won four Grand Slam titles in singles (three in the U.S. Open) and two in doubles. With 41 overall singles crowns, she ranks third among active players, behind Serena Williams (72) and Venus Williams (49), and 14th in the Open era (since 1968).
   Four of Clijsters' titles came in the Bank of the West Classic at Stanford (2001, 2003, 2005 and 2006). The tournament moved to San Jose as the Mubadala Silicon Valley Classic last year.
   Clijsters also played on Belgium's Fed Cup championship team in 2001 and won the Karen Krantzcke Sportsmanship Award, voted on by players, a record eight times.
   As a former world No. 1, Clijsters is eligible for unlimited wild cards in WTA tournaments.