“For the record, have you ever used steroids, human growth hormone or any other performance-enhancing substance?” Couric asked.

“No,” he said. Rodriguez told Couric he never felt tempted to use the substances. “I’ve never felt overmatched on the baseball field,” he said. “And I felt that if I did my work as I’ve done since I was, you know, a rookie back in Seattle, I didn’t have a problem competing at any level.”

SI.com said that Rodriguez had tested positive for the anabolic steroid Primobolan, whose chemical name is methenolone. That is the substance that prosecutors in the Bonds case say was present in tests that they contend Balco privately conducted for Bonds in 2000 and 2001. Whether those tests will be admitted as evidence in the Bonds trial is unclear.

It was Bonds, more than anyone, who prompted the 2004 raid by federal agents that eventually led to the seizure of Bonds’s result, and Rodriguez’s.

The United States Attorney’s Office in the Northern District of California was seeking to verify whether Bonds and the nine other baseball players who had testified before the Balco grand jury in San Francisco in 2003 had been truthful about their use, or nonuse, of performance-enhancing drugs.

At first, the government simply asked baseball for the results of the 2003 tests. The players union objected. It had agreed to the 2003 tests with the understanding they would be used as a survey; if more than 5 percent of the results were positive, testing with penalties would begin the next year, which is what occurred. But the union did not want to see the anonymity of the tests violated.

In the end, the agents secured search warrants to seize the tests of the 10 Balco players but then were able to go further, seizing more than 100 positive urine samples in raids on two laboratories. Bonds’s sample had actually tested negative, but authorities later had it retested at a different laboratory, and the positive results from that test may also end up as evidence in his trial.