SI.com reported last weekend that Rodriguez was among 104 players who tested positive for steroid use in 2003 while Rodriguez was a member of the Texas Rangers. Rodriguez in an interview Monday with ESPN's Peter Gammons admitted he used such substances for three years.
He said: "I did take a banned substance. For that, I'm very sorry and deeply regretful."
The SI.com report involved testing done by Major League Baseball in 2003. The test results were supposed to remain private -- although the players were informed of them -- and no penalties were to come from baseball.
In 2003 Rodriguez won his first Mast Valuable Player Award after hitting .298 with 47 home runs and 118 runs batted in -- statistics actually slightly lower than the previous two seasons. Prior to the 2001 season, Rodriguez signed a 10-year contract worth $252 million with the Rangers.
"When I arrived in Texas in 2001, I felt an enormous amount of pressure," Rodriguez said. "I needed to perform and perform at a high level every day.
"Back then (baseball) was a different culture. It was very loose. I was young. I was stupid. I was naive. I wanted to prove to everyone I was worth being one of the greatest players of all time."