Jose Guillen: Did Giants Player Use Performance-Enhancing Drugs?

(CBS/AP) Another doping scandal may be brewing in Major League Baseball.

Jose Guillen, an outfielder with the San Francisco Giants, has been linked to a federal investigation into shipments of performance-enhancing drugs, The New York Times reported.

Authorities were looking into shipments of human growth hormone (HGH) - allegedly sent to Guillen's wife in the Bay Area - just before the postseason began, according to the Times.

"I don't know anything about it and right now I don't have a comment," manager Bruce Bochy said.

Guillen, 34, has been tied to performance-enhancing drugs before. The San Francisco Chronicle reported in 2007 that he allegedly purchased more than $19,000 worth of HGH, steroids and other drugs from the Palm Beach Rejuvenation Center between May 2002 and June 2005.

Doctors use HGH to treat a variety of conditions, including short stature in children and muscle wasting in adults. But as for boosting athletic performance, studies show conflicting results.

"Some short-term studies showed that older adults increased their endurance and strength, with increased muscle and decreased fat mass, according to the Hormone Foundation. "But other studies did not show similar benefits."

And the foundation says there are risks to using HGH, including joint and muscle pain and heart disease.

Not that Major League Baseball would know if players are using HGH.

Though baseball now tests for HGH in the minor leagues, the MLB players' association has long been against blood testing for HGH.