Major League Baseball announced Monday that it has approved a roster substitution for the New York Yankees due to an injury sustained by outfielder Melky Cabrera. Cabrera will be replaced by infielder Ramiro Pena for the remainder of the 2009 World Series. MLB postseason rules provide that injured players can be replaced during the World Series if the severity of the injury, as determined by Major League Baseball, is such that it would require a disabled list assignment during the regular season.