WASHINGTON — Andy Pettitte and Roger Clemens sat some 20 feet apart, Pettitte on the witness stand and Clemens at the defense table trying to avoid going to jail. The topic: a remark about human growth hormone Pettitte recalled hearing from his longtime teammate, mentor and workout partner a dozen years ago.

“Roger had mentioned to me that he had taken HGH,” Pettitte testified. “And that it could help with recovery, and that’s really all I remember about the conversation.”

The rest of the details are fuzzy. Pettitte went on acknowledge that the words were said in passing during a workout.

It’s a conversation that Clemens has famously claimed that Pettitte “misremembers.”

The right-hander on trial who won 354 major league games and the lefty on the stand with 240 wins had an awkward reunion Tuesday, Day 8 in the retrial of charges that Clemens lied when he told Congress in 2008 that he never used steroids or HGH.

Pettitte’s appearance enlivened the proceedings and came without warning. The government interrupted testimony from the trial’s first witness to call Pettitte just before noon.

Pettitte testified mostly with his hands clasped in front of him and rarely looked at Clemens, even during the lengthy delays when lawyers held conferences at the judge’s bench.

Clemens frequently took notes. The two haven’t spoken recently because of the trial, but Pettitte nevertheless said he found it difficult to testify because he still considers Clemens a good friend.

Pettitte is crucial to a government case that will otherwise rely heavily on the testimony of Brian McNamee, who worked as a strength coach for both Clemens and Pettitte and has said he injected both men with performance-enhancing substances.

Pettitte has acknowledged he received HGH from McNamee; Clemens has not. Pettitte told the jury about the time he used HGH in 2002 while recovering from an injury, but he wasn’t allowed to say he was injected by McNamee because the judge ruled that inadmissible.

Pettitte said he used HGH one other time, in 2004. He said he regretted it both times he tried it, that he doesn’t think it helped him physically and that it has tarnished his name.

Asked to recall the conversation in which Clemens supposedly admitted to using HGH, Pettitte remembered it taking place during a workout at Clemens’ house in Texas during the 1999-2000 offseason. Maybe inside the gym. Maybe outside.

Then, under cross-examination from one of Clemens’ lawyers, Pettitte revealed how tenuous his account might seem to the jury. Attorney Michael Attanassio asked if it came amid a “lot of huffing and puffing” that accompanies a workout.

“Yes,” Pettitte answered.

Pettitte was then asked if Clemens’ remark was made “in passing” — as opposed to in a “focused conversation.”

“I would say so,” Pettitte said.

Pettitte will return to the stand today.

Pettitte also recalled the other time he spoke with Clemens about HGH, during the media swirl surrounding earlier congressional hearings – in 2005 – on drug use in sports. Both were playing for the Astros, and Pettitte asked Clemens at spring training what Clemens would say if asked by reporters about HGH use.

Clemens responded: “What are you talking about?” according to Pettitte, and that Pettitte must have misunderstood the 1999-2000 conversation.

“He said, ‘My wife used it,”‘ Pettitte said.

“Obviously I was a little flustered,” Pettitte said, “because I thought that he told me that he did.”