McGwire ended more than a decade of speculation when he acknowledged that he used steroids during much of his Major League playing career, including in 1998, when he broke Major League Baseball's single-season home run record. However, he insisted that he took the substances only to aid in his recovery from injury and only in low doses. And he said repeatedly that he did not believe the drugs had increased his ability to play once he took the field.
McGwire initially made the revelation in a statement issued to news outlets on Monday afternoon, then addressed the situation further in an interview with Bob Costas on MLB Network.
"I did it [for] health purposes," McGwire told Costas. "If you look at my career, injured '93, '94, '95, '96, I was a walking M*A*S*H unit. I told my dad yesterday when I finally had to tell him about this. I remember calling him in '96. I was so frustrated with injuries, I wanted to retire. He's the one who told me to stick it out. At that time I was using steroids thinking it was going to help me. It was brought to my attention that it was going to help me heal faster, make my body feel back to normal."
Asked repeatedly by Costas if he believed that his statistics and records were legitimate in light of the disclosure, McGwire did not budge.
"Absolutely," he said. "I truly believe so. I was given this gift by the man upstairs. My track record as far as hitting home runs ... my first at-bat in the league was a home run. They still talk about the home runs I hit in high school. They still talk about the home runs I hit in [American] Legion. They still talk about the home runs I hit in college [USC] -- I led the nation in home runs. They still talk about the home runs I hit in the Minor Leagues.
"I was given the gift to hit home runs. The thing is about the years you were talking about, you go back to '93 and '94, those are the two years that I was really injured where I missed basically three-quarters of the season. That was the first time in my life that I sat back and I really had to understand what this game was about. I started studying pitchers. I started understanding how they try to get you out. And during that, my swing was changing."
McGwire teared up several times during the interview and at times needed a moment to compose himself. He was visibly and audibly shaken by the experience. However, given an opportunity to take a break early in the interview, McGwire declined. Costas pressed him determinedly, subjecting him to pointed questions but not devolving into an attack.
The Cardinals announced in October that McGwire would be the team's hitting coach for the 2010 season, and in three separate statements on Monday, club representatives pledged their continuing support for him. McGwire said that the timing of his announcement was tied to the club's hiring of him. In fact, he said that he wanted to admit his actions in 2005, when he appeared before a Congressional panel to discuss steroids in baseball.
However, McGwire said, to do so could have exposed him to prosecution, because his attorneys were unable to secure immunity prior to his testimony. Thus, McGwire uttered the famous line that he was "not here to talk about the past," a line that has followed him ever since.
"I was ready, willing and prepared to talk about this," McGwire said. "I wanted to talk about this. I wanted to get this off my chest. ... It was killing me. It was absolutely killing my heart. But I had to do what I had to do to protect myself, to protect my family, to protect my friends."
Baseball Commissioner Bud Selig likewise issued a statement in support of the retired slugger.
"I am pleased that Mark McGwire has confronted his use of performance-enhancing substances as a player," Selig said. "Being truthful is always the correct course of action, which is why I had commissioned Senator George Mitchell to conduct his investigation. This statement of contrition, I believe, will make Mark's reentry into the game much smoother and easier."
According to McGwire's statement, his usage of PEDs spanned a large portion of his career, which included parts or all of 16 seasons. He also told Costas that he tried human growth hormone "once, twice maybe." His first full season in the Majors was 1987, so McGwire acknowledges beginning to use after his third full season. The 1993 campaign was the first in which he played fewer than 139 games, as he was limited by foot injuries.
"The names [of the drugs], I don't remember," McGwire told Costas. "But I did injectables. I preferred the orals. The steroids that I did were on a very, very low dosage. I didn't want to take a lot of that. I didn't want to look like an Arnold Schwarzenegger or Lou Ferrigno. The most I ever got in weight, my weight was 250, and at the end of the season, 235-240. I took very, very low dosages just because I wanted my body to feel normal."
After missing large chunks of the 1993, 1994 and 1995 seasons, McGwire returned to form with a vengeance in 1996, hitting a then-career-high 52 home runs and batting .312 with a .467 on-base percentage. He followed that up with a big 1997, and was traded to St. Louis that year, then broke Roger Maris' single-season homer record when he hit 70 in 1998. He was insistent that the home runs were not a product of his physique or what he was taking.
Tony La Russa, who was McGwire's manager for the vast majority of his career, came to his friend's defense.
"No one on the teams I managed worked harder or better than Mark," La Russa said in a statement issued by the club. "And now, his willingness to admit mistakes, express his regret, and explain the circumstances that led him to use steroids add to my respect for him."
La Russa was one of many people to receive a phone call and an apology from McGwire prior to his announcement. McGwire also talked to some current teammates, including slugger Albert Pujols and infielder Brendan Ryan, and left a message for Matt Holliday. Ryan and Holliday are among several Cardinals who have received hitting instruction from McGwire in recent winters.
McGwire also said he called Pat Maris, the widow of Roger Maris. The Maris family's support of McGwire was one of the most compelling subplots of the 1998 home run chase.
"I think she was shocked that I called her," McGwire said. "I felt that I needed to do that. They had been great supporters of mine. She was disappointed, and she has every right to be. And I couldn't tell her [enough] how so sorry I was."
Despite his lengthy admissions, though, McGwire did take issue with one element of how his story has been portrayed. He adamantly denied the allegations from former teammate Jose Canseco that the two had injected steroids together repeatedly in the clubhouse prior to games.
"There's absolutely no truth to that whatsoever," McGwire said.
Matthew Leach is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.