In 2003, Jason Giambi told a grand jury investigating BALCO, Barry Bonds’ favorite pharmacy, that he had used steroids and human growth hormone. A year later, excerpts of his testimony were leaked to and published by the San Francisco Chronicle.

Soon afterward, Giambi “unburdened” himself, apologizing but never quite saying exactly what he was sorry for, to the assembled media at Yankee Stadium.

In none of those cases was there any adverse effect on the career or reputation of Giambi, although behind the scenes, the Yankees looked into the legal ramifications of releasing him from the remaining years on his contract, which would have provided them with a most welcome $60-million refund.

If anything, Giambi benefited from his “disclosure,” partial though it may have been, in the court of public opinion.

At least Giambi was “honest,” everyone said. Not like that arrogant Barry Bonds, who steadfastly refused to answer any questions regarding steroids even after federal investigators found tainted syringes in his garbage, and not like that surly Gary Sheffield, who told anyone who tried to broach the subject with him to “get the – – out of my face.”

Somehow, in this age of watered-down standards for everything, Giambi’s non-apologetic apology passed for the kind of heartfelt contrition most of us have always been suckers for.

Now, he has done it again, and gone a step further, telling USA Today “I was wrong for doing that stuff,” and suggesting that Major League Baseball owed the fans an apology.

For this, Giambi is in hot water. The commissioner’s office, taking a break in its dithering over whether or not Bud Selig should share the disgrace of Bonds’ 756th home run, says it will “look into” Giambi’s remarks in contemplation of some sort of punishment.

The Yankees, under a gag order from MLB, are no doubt re-investigating ways to void the remainder of Giambi’s contract, which runs out after the 2008 season.

But where was Major League Baseball in 2001, when the “S-word” was purposefully excised from Giambi’s contract? Where were the Yankees in 2003, when both Giambi and Sheffield testified to the grand jury? Why didn’t anyone “look into” Giambi’s remarks, made under oath, when the transcripts were published in 2004?

For that matter, why didn’t baseball begin its “investigation” into steroid use in 2000 when Sheffield told HBO’s “Real Sports” that “five or six players” on every team in the majors were using?

How about as far back as 1998, when the fateful bottle of andro was discovered in the locker of Mark McGwire, the great redheaded god who was to save baseball? Selig didn’t want to know about that.

Nobody was too steamed up over steroids back then because at the time, the juice wasn’t just working for the players, it was working for the entire sport. It took Jose Canseco’s book and a bunch of major-league ballplayers either too dumb or too arrogant to heed the warning handed down in 2004.

Now, Major League Baseball turns on its co-conspirators under the illusion of cleaning up a mess they created.