His reported testimony that he used steroids might lead the Yankees to terminate his $120 million contract and allow baseball commissioner Bud Selig (search) to discipline him.
Giambi said he injected himself with human growth hormone in 2003 and used steroids for at least three seasons, according to a grand jury transcript reviewed by the San Francisco Chronicle.
His testimony last December, before a federal grand jury investigating illegal steroid distribution, contradicts his public proclamations that he never used performance-enhancing drugs.
Penalties for steroid use in baseball began in 2003, but testing that identified players didn't start until the next season. While discipline is spelled out for positive tests and criminal convictions, admission of steroid use is not addressed, possibly giving Selig an opening to punish Giambi.
Selig repeatedly has called for year-round random testing and harsher penalties, but management and the players' association have failed to reach an agreement. The contract runs through the 2006 season.
"I've been saying for many months: I instituted a very, very tough program in the minor leagues on steroids in 2001. We need to have that program at the major league level," Selig said Thursday in Washington, D.C. "We're going to leave no stone unturned until we have that policy in place by spring training 2005."
Giambi, the 2000 American League MVP with Oakland, signed a seven-year contract with the Yankees before the 2002 season, the sixth-highest deal in baseball history.
Bothered by an injured knee, Giambi hit just .250 in 2003. He batted .208 and played in only 80 games last season, missing time because of a sprained right ankle, fatigue and a benign tumor, which the New York Daily News reported was in his pituitary gland. The Yankees did not even include him on their postseason roster.
Giambi reportedly testified that one of the drugs he thought he used was Clomid, a female fertility drug that some medical experts say can exacerbate a pituitary tumor.
Giambi's agent, Arn Tellem, didn't return telephone calls seeking comment.
New York still owes Giambi $82 million, but the Yankees might be able to get out of the deal.
They could argue Giambi's use of steroids violated his contract, allowing them to terminate it; violated the guarantee language of the deal, allowing them to release him at a fraction of the remaining money; or caused him to be injured or unavailable, meaning he was paid at a time when he was at less than full strength.
"We have met with the commissioner's office today and will continue to work with them to obtain all of the facts in this matter," Yankees president Randy Levine said. "We have made no decisions and will keep all of our options open."
Meanwhile, U.S. Attorney Kevin Ryan said his office was concerned about the leaks to the Chronicle and asked the Justice Department to investigate. "Violations of grand jury secrecy rules will not be tolerated," Ryan said.
Giambi came to spring training this year noticeably trimmer. Asked in February whether he had ever taken performance-enhancing drugs, Giambi said: "Are you talking about steroids? No."
However, he told grand jurors he used steroids during the 2001-2003 seasons, the Chronicle reported Thursday. He testified how he injected human growth hormone, known as hGH, in his stomach, testosterone into his buttocks, rubbed an undetectable steroid knows as "the cream" on his body and placed drops of another, called "the clear," under his tongue, the newspaper said.
Giambi testified that he obtained several different steroids from Barry Bonds' personal trainer, Greg Anderson, one of four men indicted by the grand jury probing the Bay Area Laboratory Co-Operative. He said he got the hGH from a gym in Las Vegas.
Tony Serra, Anderson's lawyer, said Anderson "never knowingly provided illegal substances to anyone."
Gene Orza, the chief operating officer of the players' association, declined comment.
Anderson, BALCO founder Victor Conte, BALCO vice president James Valente and track coach Remi Korchemny have pleaded not guilty to charges that include steroid distribution.
In an interview to be shown on ABC's "20/20" on Friday night, Conte mocked MLB's drug-testing program.
"Let me tell you the biggest joke of all: I would guesstimate that more than 50 percent of the athletes are taking some form of anabolic steroids," he said.
Giambi was among dozens of elite athletes — including Bonds, Gary Sheffield and track stars Tim Montgomery and Marion Jones — who testified before the grand jury last year under a promise of limited immunity from prosecution.