The Times is reporting Guillen, 34, was kept off the Giants' postseason roster because federal authorities are looking into whether he had human growth hormone mailed to his wife at their Bay Area home. Team Manager Bruce Bochy had said Guillen was left off the roster for all three rounds of the postseason play because of a nagging neck injury.
A person with Major League Baseball confirmed the investigation with the Associated Press. Officials and attorneys with the Giants have declined to comment on the matter. MLB officials have opened their own investigation, according to lawyers.
Guillen's teammates were surprised to hear of the accusations.
Guillen, an outfielder and heavy-hitter, has been tied to performance-enhancing drugs before. In 2007, the Chronicle reported Guillen allegedly bought more than $19,000 worth of HGH, steroids and other drugs from the Palm Beach Rejuvenation Center between May 2002 and June 2005.
Guillen has played for 10 teams since he joined the MLB in 1997. He's a .270 career hitter with 214 homers and 887 RBIs. The Giants acquired him from the Kansas City Royals in mid-August.
The Giants beat the Texas Rangers 9-0 in Game 2 of the World Series Thursday night at AT&T Park.