Serena Williams injures knee, pulls out of semifinal match

STANFORD, Calif. -- Top-seeded Serena Williams injured her left knee and pulled out of the Bank of the West Classic on Saturday, becoming the third singles player on the U.S. Olympic women's tennis team with a knee injury. She retired while trailing during the second set of her semifinal match against qualifier Aleksandra Wozniak. Williams' sister Venus and Lindsay Davenport, the other U.S. Olympic singles players, have already pulled out of next week's East West Bank Classic in Carson, Calif., with right knee injuries. Serena Williams struggled from the start against the 85th-ranked Wozniak and first called for the trainer when trailing 5-2 in the first set. She got the knee heavily taped by the trainer and came out to finish the set, but appeared to struggle to plant on her injured leg. Wozniak held serve to win the set and... [read full story]