"Again, it was such a loosey-goosey era," Rodriguez said. "I'm guilty for a lot of things. I'm guilty for being negligent, naive, not asking all the right questions. And to be quite honest, I don't know exactly what substance I was guilty of using."

A three-time AL Most Valuable Player, Rodriguez blamed himself and his $252 million contract he signed with the Rangers in 2001 for his decision to use PEDs.

"I felt a tremendous pressure to play, and play really well" in Texas, the New York Yankees third baseman said. "I had just signed this enormous contract ... I felt like I needed something, a push, without over-investigating what I was taking, to get me to the next level."

Rodriguez also said part of the reason he started using drugs was the heat in Texas.

"Can I have an edge just to get out there and play every day?" he said to himself. "You basically end up trusting the wrong people. You end up, you know, not being very careful about what you're ingesting."

Rodriguez added: "I am sorry for my Texas years. I apologize to the fans of Texas."

Rodriguez, who joined the Yankees for the 2004 season after a trade from Texas, said his years as a Yankee "have been clean."

"I've played the best baseball of my career since," he said. "I've won two MVPs since and I've never felt better in my career. Of that I'm very proud of."

The Yankees issued a statement.

"We urged Alex to be completely open, honest and forthcoming in addressing his use of performance-enhancing drugs," it read. "We take him at his word that he was. Although we are disappointed in the mistake he spoke to today, we realize that Alex -- like all of us -- is a human being not immune to fault.

"We speak often about the members of this organization being part of a family, and that is never more true than in times of adversity. Alex took a big step by admitting his mistake, and while there is no condoning the use of performance-enhancing drugs, we respect his decision to take accountability for his actions. We support Alex, and we will do everything we can to help him deal with this challenge and prepare for the upcoming season."

Rodriguez described the last days' turn of events as the biggest challenge of his life but added it felt good to be honest about what he's done in the past.

"It's been a rough 15 months here for me," Rodriguez said.

He added: "I was stupid for three years. I was very, very stupid" and, later said: "The more honest we can all be, the quicker we can get baseball [back] to where it needs to be."

"When you take this gorilla and this monkey off your back, you realize that honesty is the only way," Rodriguez said. "I'm finally beginning to grow up. I'm pretty tired of being stupid and selfish, you know, about myself. The truth needed to come out a long time ago. I'm glad it's coming out today."

He said he stopped using during spring training 2003, when he sustained a neck injury. It was just as baseball started its drug-testing survey. It was only in 2004 that testing with penalties began.

"It wasn't a real dramatic day once I arrived in Texas that something monumental happened in my life," he said. "The point of the matter was that I started experimenting with things that today are not legal or today are not accepted and today you would get in a lot of trouble for."

He said the culture earlier this decade of taking performance-enhancing substances was "prevalent." "There were a lot of people doing a lot of things," Rodriguez said, noting that he wasn't specifically pointing out the Rangers.

"You have nutritionists, you have doctors, you have trainers. That's the right question today: Where did you get it? We're in the era of BALCO," Rodriguez said. "There's many things that you can take that are banned substances. I mean, there's things that have been removed from GNC today that would trigger a positive test."

Rodriguez said he was told by Gene Orza, the chief operating officer of the MLB Players Association, that he might, or might not, have tested positive in the 2003 survey. That conversation happened during the 2004 season. A source told ESPN on Saturday that Rodriguez knew he had failed the test.

According to the Mitchell report, all players who failed the test in 2003 were notified by September 2004.

Rodriguez said he didn't know for sure he had failed a test until Sports Illustrated contacted him last week.

Orza told The New York Times he did not tip off Rodriguez to a test at the conclusion of the '04 season. "It's not true. Simple as that," he told the newspaper on Monday via e-mail.

Union head Donald Fehr reiterated in a statement that there was no improper tipping of players.

"Any allegations that Gene Orza or any other MLBPA official acted improperly are wrong," he said.

Fehr said the union first received test results on Nov. 11, 2003, that the results were finalized two days later and that players were notified the following day, a Friday.

"Promptly thereafter, the first steps were taken to begin the process of destruction of the testing materials and records," Fehr said. "On Nov. 19, however, we learned that the government had issued a subpoena. Upon learning this, we concluded, of course, that it would be improper to proceed with the destruction of the materials."

Rodriguez said Orza told him in August or September 2004 about the list of names that had been seized by federal investigators.

"He said there's a government list. There's 104 players in it. You might or might not have tested positive," Rodriguez said.

Rodriguez also told ESPN's Gammons of his 2007 interview with Katie Couric on "60 Minutes," when he denied ever using steroids, that "at the time, Peter, I wasn't even being truthful with myself. How am I going to be truthful with Katie or CBS?"

Rodriguez also criticized Sports Illustrated and said Selena Roberts, one of its reporters who covered the story, stalked him. He also accused Roberts of trying to break into his home last week while his two daughters were sleeping.

Sports Illustrated released a statement, saying it "stands by the story and the professional manner in which it was reported. Selena Roberts is a distinguished journalist and her reporting in this case led to Alex Rodriguez's admission that he used performance-enhancing drugs."

"The allegations made by Alex Rodriguez are absurd," said Roberts, in the statement. "I've never set foot in the lobby of Alex's New York apartment building, never spoken to the University of Miami police, and never set foot on his home property or been cited by the Miami Police for doing so."

ESPN obtained a copy of a Miami Beach police report on Monday night that indicates there was an incident between Roberts and a security guard at the guard shack of Rodriguez's community on Feb. 5. There is no indication Roberts was at Rodriguez's home, and no charges were filed.

"SI has a long history of investigative reporting, and the work by Selena Roberts stands solidly in that tradition," Sports Illustrated group editor Terry McDonell said in a statement.

In his 2008 book, "Vindicated: Big Names, Big Liars, and The Battle to Save Baseball," Jose Canseco claimed he introduced Rodriguez to a steroids dealer. Canseco, who has admitted using steroids, subsequently said he had no knowledge of any drug use by Rodriguez.

"They are looking in the wrong places," Canseco said in a text message to The Associated Press. "This is a 25-year cover-up. The true criminals are Gene Orza, Donald Fehr and [commissioner] Bud [Selig]. Investigate them, and you will have all the answers."

Rep. Elijah Cummings, a Maryland Democrat who sits on the House committee that brought Roger Clemens, Mark McGwire and other baseball players to Capitol Hill in recent years, favored a congressional hearing with Rodriguez.

"It would be good perhaps for us to sit down and talk to him," Cummings said in a telephone interview. "I would think that he would want to cooperate with us so that the Congress would have the information it may need."

Former Yankees manager Joe Torre expressed his surprise.

"We all hope that this information that has come out is going to benefit the game of baseball in the long run," he said. "It blindsided me that it was so widespread. We all have to take blame for this. I had never really heard anything in connection to him. When you watch his work ethic, the time he puts in at batting practice and in the weight room, I had no reason to question him. He has the most ability of any player I've seen.

"It's going to be tough for him but I'm happy that he came out, faced the music and took responsibility for it."

Rodriguez is still expected to attend an event Friday at the University of Miami, which is renaming its baseball field in his honor. He gave $3.9 million to the school in 2003, the largest gift ever to the Hurricanes' baseball program and money that provided much of the resources needed for renovating the existing on-campus stadium. In return, the baseball complex will be called Mark Light Field at Alex Rodriguez Park.

Despite the scandal, the facility will continue to bear Rodriguez's name, a university official told AP on Monday. The official spoke on condition of anonymity because of the matter's sensitive nature.

Miami baseball players and coaches were not available for comment, spokesman Mark Pray said.

Information from The Associated Press was used in this report.