Kelly Blair, who owns a gym in Pasadena, Texas, was the source of the substance, the New York Daily News reported Sunday.
Pettitte, who has admitted using HGH in 2004, told congressional attorneys that he received it from his father, Tom Pettitte, who has had serious health problems. In his deposition, Pettitte said his father got the drugs from a trainer at a gym where he worked out but did not identify the trainer.
The Daily News reported that Blair sold HGH and steroids to customers at 1-on-1 Elite Personal Fitness. Blair did not respond to the newspaper's requests for comment.
Pettitte, who is scheduled to report to spring training Monday, and Blair attended nearby Deer Park High School, east of Houston, at the same time.
Pettitte planned to make his first public comments since telling a congressional committee that
Roger Clemens had spoken with him about using performance-enhancing drugs.
"The sooner he gets here, the better it will be, to get it over, and just do what he has to do," Mariano Rivera said Sunday.
Pettitte was excused from testifying publicly in Washington last week after he gave a deposition and an affidavit. In addition to his December admission that he used human growth hormone for two days in 2002 while with the Yankees, he said he injected himself with HGH for one day in 2004 while with the Houston Astros after obtaining two syringes from his father.
Pettitte also said Roger Clemens, his friend and former teammate, had discussed nearly a decade ago using HGH. In addition, Pettitte testified Brian McNamee, the former personal trainer for Clemens and Pettitte, had spoken in 2003 or 2004 about steroids use by Clemens.
"There's just necessary steps on this ladder as he climbs back, obviously, up on that mound starting every fifth day for us," Yankees general manager Brian Cashman said. "So tomorrow is step one in that process."
Cashman has spoken on the phone with Pettitte, who planned to travel Monday morning from his home in suburban Houston, but Cashman wouldn't detail those talks. Pettitte was given permission to report to spring training four days after other Yankees pitchers because of what new manager Joe Girardi said were "loose ends that he had to tie up."
"I think he wants to get his life back to normal. I don't think Andy is a guy who goes into hiding," said Girardi, who planned to attend the news conference. "I think he wants to get back to doing what he wants to do, and that's pitch for the New York Yankees."
Pettitte, who will be accompanied by lawyer Jay Reisinger, does not appear to be at risk of a suspension for his admissions. HGH was not banned by players and owners until January 2005.
But he could remain ensnared between McNamee and Clemens, who denies allegations that he used performance-enhancing drugs. Dealing with his first controversy since he was hired to replace Joe Torre, Girardi said it was too soon to tell whether the matter will end soon for Pettitte.
"I think a lot of that depends on what happens with Roger and what he continues to do. If that was to all die down, I think it would pretty much go away," Girardi said. "But, obviously, there's some litigation there that Andy might be a part of, so from that standpoint, it could linger."
Clemens has filed a civil suit against McNamee claiming defamation, and there could be a criminal investigation of the conflicting accounts given Congress by Clemens and McNamee.
Girardi understands any additional admissions of drug use by Pettitte "would become a huge story."
"But my thought is Andy has probably told everything that there is," Girardi said.
During the season, spectators on the road are likely to remind Pettitte of HGH use.
"You know how the fans are. They're going to say anything to distract the pitcher," Rivera said. "Hopefully, it's not too bad, because it always happens."
A 35-year-old left-hander with 201 regular-season wins, Pettitte debated retiring after going 15-9 with a 4.05 ERA in his first season back with New York following three years on the Astros. He announced Dec. 3 that he would accept the Yankees' $16 million standing offer to return for another year. That was two days before McNamee called Jim Murray, an employee of the agency that represents Clemens and Pettitte, and said the two players would be in the Mitchell Report.
While disapproving of Pettitte's HGH use, Cashman said it didn't diminish Pettitte in his view.
"Whatever took place, Andy is a good person. Obviously he's admitted to some mistakes, but he's a good man. He really is," Cashman said. "I say Roger is a good guy, too. One is admitting to things -- there's denials on Roger's case. But the Roger Clemens I also know is an extremely good person who's done a lot for a lot of people and was a good teammate."