Chinese rookie Yi Jianlian from Milwaukee Bucks sprained his left knee on Wednesday in the second quarter against the hosts Washington Wizards in a National Basketball Association game.

Milwaukee Bucks Yi Jianlian (L) waits for breaking through the defense of Washington Wizards Andray Blatche during their NBA basketball game in Washington April 2, 2008. Milwaukee Bucks won 110-109.

It's fourth injury happened to Yi in two months. He had played only six minutes before he left the court with assistance three minutes into the second quarter. He was scoreless in the game, going 0-for-1 from the field.

"I feel more and more in pain and I cannot put weight on the left leg right now," said Yi.

He said the Bucks trainer had examined his right knee just after he left the court and asked him to have a thorough exam back to Milwaukee on Thursday.

The 20-year-old Yi was sidelined for six games last month by a right wrist sprain and a left ankle sprain and was off two matches on Feb. when he was injured in his right shoulder in a game against the Houston Rockets.

The latest injury comes barely four months before the Olympics, where Yi and NBA star center Yao Ming will be counted upon to lead China to get the best result in the Olympics in their homeland.

Yao, missing the remainder of the season after suffering a broken left ankle, is expected back for the Beijing Olympics.