CHICAGO - -Another chapter in the seemingly endless steroid-era saga - one played out in locker rooms and court- rooms, the halls of Congress and eventually the Hall of Fame - was rewritten Monday with Mark McGwire's admission that "I used steroids during my playing career, and I apologize."

More than a decade after he and Sammy Sosa staged a smashingly successful soap-opera-like home run derby, McGwire confessed that his part was tainted, saying, "After all this time, I want to come clean."

But while the chapter on McGwire's involvement apparently has been completed with Monday's hardly surprising confession, the entire book is far from finished.

Sosa, who appeared with McGwire in 2005 before a House Government Reform committee's hearing on steroids in baseball, has been implicated by The New York Times as failing a 2003 drug test.

And the national pastime's all-time home run king, Barry Bonds, remains under indictment for perjury for denying he knowingly used performance-enhancing drugs.

McGwire, infamously, became part of that nationally televised congressional hearing, repeatedly taking the Fifth Amendment and saying he refused to "talk about the past."

The baseball panel included Sosa and Rafael Palmeiro, both former Orioles.

"To be clear, I have never taken illegal performance-enhancing drugs," Sosa told congressmen in sworn testimony. "I have not broken the laws of the United States or the laws of the Dominican Republic. I have been tested as recently as 2004, and I am clean."

Palmeiro waggled his fingers at the panel and proclaimed, "I have never used steroids, period."

Palmeiro was suspended six months later after testing positive for performance-enhancing drugs.

Neither those tests, nor even rules regarding steroids, were baseball law in 1998 or in 2001 when McGwire retired.

He left the game in part because he had tired of the constant media allegations.

On Monday, in his admission statement released to the Chicago Tribune and other media outlets, McGwire said:

"I was not in a position to do [this] five years ago in my congressional testimony, but now I feel an obligation to discuss this and to answer questions about it. I'll do that, and then I just want to help my team."

McGwire was hired as the Cardinals' hitting coach in late November, which helped prompt his disclosure.

"I never knew when, but I always knew this day would come," he said, also saying to media outlets later that "I hid it from everybody.

"I wish I had never touched steroids. It was foolish and it was a mistake. I truly apologize. Looking back, I wish I had never played during the steroid era."

And yet he did. And he was a huge part of its results, with his home run totals (70 in 1998, 583 in his career) - partly based on his Popeye-like forearms - that included leading the league in that category four times and, in that stirring 1998 season, shattering Roger Maris' nearly four-decades-old record of 61 homers.

(Sosa hit 66 that season, and Bonds broke McGwire's mark in 2001 with 73.)

How long did he use steroids and perhaps human growth hormone, and how frequently?

While McGwire, a weightlifting fanatic, says steroids helped him overcome injuries, those questions might never be answered.

"I remember trying steroids very briefly in the 1989-1990 offseason and then after I was injured in 1993, I used steroids again," he said in his statement. "I used them on occasion throughout the '90s, including during the 1998 season."

In a game Sept. 8, 1998, at Busch Stadium in St. Louis, McGwire hit his 62nd home run against the Cubs, an event that riveted the nation and was labeled that night by commissioner Bud Selig as "clearly one of the most historic nights in baseball history."

Selig said in a statement Monday that McGwire's admission "will make Mark's re-entry into the game much smoother and easier."

Whether McGwire, Bonds or Sosa will ever be inducted into the Hall of Fame - despite their glittering statistics - remains another chapter for the steroid-era book.

McGwire, a 12-time All-Star, has never received one-fourth of the necessary votes from baseball writers during his four years on the ballot.

None of the others is on the ballot yet.

"I'm sure people will wonder if I could have hit all those home runs had I never taken steroids," he said. "I had good years when I didn't take any and I had bad years when I didn't take any. I had good years when I took steroids and I had bad years when I took steroids.

"But no matter what, I shouldn't have done it, and for that I'm truly sorry."