Kevin Youkilis is out of the WBC because of a sprained left ankle.
Youkilis returned to Red Sox camp in Fort Myers, Fla., to get an MRI. He injured it two days ago and it grew worse last night.
Derrek Lee is the only other first baseman eligible to be added, but he is hurt (knee) and has been ruled out by the Cubs. Adam Dunn is playing first base in Wednesday night's game against Venezuela, against the preferences of the Nationals. He appears to be their only option for the semifinals, which will be played in Los Angeles this weekend.
Youkilis has started all six games for the U.S. team. Although he's hitting just .182 (4-for-22) in the World Baseball Classic, he's tied for the WBC lead with three home runs.
Red Sox doctors diagnosed first baseman Kevin Youkilis as having a mild left ankle sprain and Achilles tendintis in his left foot. Youkilis, who left Team USA after experiencing pain in his left ankle Tuesday, will wear a cast for several days and, according to a statement released by the Red Sox, "is not expected to miss significant time."