Mark Letendre, 50, told The Associated Press on Tuesday that he testified for about an hour Feb. 14.
"It was all pretty vanilla," Letendre said. "I'm pretty far removed from it."
Since U.S. Attorney Kevin Ryan was fired in December, speculation has mounted that the Department of Justice would quietly extinguish the long-running investigation into whether Bonds lied under oath when he told a 2003 grand jury that he didn't knowingly take performance-enhancing drugs.
"There is absolutely no doubt that the U.S. attorney is still running a grand jury and still taking evidence that involves Bonds," said Michael Rains, the lawyer for Bonds. "There is still an active effort to indict Barry."
Letendre was asked about Bonds' size and confirmed the slugger hurt his elbow in 1999. Bonds' former girlfriend Kimberly Bell told a previous grand jury that Bonds blamed the 1999 elbow injury on steroid use. Bonds missed seven weeks that season after undergoing surgery to remove a bone spur and repair a damaged tendon in his left arm.
Bonds' supporters maintain the investigation is little more than an expensive, high-profile smear campaign of an unpopular baseball player approaching a hallowed Major League Baseball record. With 735 home runs, Bonds is 20 shy of Hank Aaron's all-time record.
Stan Conte, Letendre's successor as the Giants' head trainer, and Arthur Ting, Bond's surgeon, also have testified before a grand jury. Bonds' personal trainer, Greg Anderson, remains jailed for refusing to testify.
The grand jury is investigating whether Bonds committed perjury when he testified that he believed a clear substance and a cream, given to him by Anderson, were flaxseed oil and arthritis balm.