The seven-time Cy Young Award winner, a fiery look in his eyes and stubble on his face, told CBS's Mike Wallace that he would have spoken with baseball drug investigator George Mitchell had he been aware McNamee accused him of using steroids and HGH.
Clemens, the most prominent player implicated in last month's Mitchell Report, steadfastly maintained his innocence and called McNamee's allegations "totally false."
"If he's doing that to me, I should have a third ear coming out of my forehead. I should be pulling tractors with my teeth," said Clemens, who wore a lavender button-down shirt during the interview, taped Dec. 28 at his home in Katy, Texas.
"I thought it was an impassioned, disingenuous and desperate plea," said Earl Ward, McNamee's primary lawyer.
One of the few revelations in the much-hyped interview came when Clemens was asked whether he could conceivably take a lie detector test.
"Yeah," he answered. "I don't know if they're good or bad."
Clemens is scheduled to hold a news conference Monday in Houston, part of his campaign to clear his name. In addition, the House Committee on Oversight and Government Reform has asked Clemens, Pettitte and McNamee to testify, heightening the stakes and putting them potentially in legal jeopardy.
Former Yankees teammate Chuck Knoblauch, McNamee and former Mets clubhouse attendant Kirk Radomski, who allegedly supplied McNamee with performance-enhancing drugs, also have been asked to testify.
Lawyers for Clemens and McNamee have said their clients are willing to testify. Clemens' attorney, Rusty Hardin, wouldn't commit to the date.
Richard Emery, another of McNamee's lawyers, said he would welcome testimony from Clemens.
"If Congress calls him, he pretty much has to take the Fifth, and if he takes the Fifth, nobody will ever believe him again and all this effort has gone down the drain," Emery said. "And if he doesn't take the Fifth, it's very hard to imagine that a prosecutor isn't going to pursue this. So I think he's put himself in a terrible corner."
Clemens said his lawyer advised him not to speak with Mitchell, who spent 20 months on his investigation.
"If I would've known what this man, what Brian McNamee (had) said in this report, I would have been down there in a heartbeat to take care of it," Clemens said.
Only two active players, Jason Giambi and Frank Thomas, spoke with Mitchell, a Boston Red Sox director and a former Senate majority leader.
On Friday, Clemens did speak with McNamee by telephone, an individual close to the situation said, speaking on condition of anonymity because public comments weren't authorized. The conversation first was reported Sunday by Newsday.
The individual would not say what was discussed between the two.
In excerpts of the Dec. 28 interview that were released Thursday, Clemens said McNamee, his former personal trainer, injected him with vitamin B-12 and the painkiller lidocaine. In the full 14-minute broadcast, Clemens also said he was given an injection of toradol under the supervision of the New York Yankees.
McNamee told Mitchell he injected Clemens with steroids and HGH about 16-to-21 times during 1998, 2000 and 2001 -- before baseball players and owners agreed to ban performance-enhancing substances.
Clemens said the cost of litigation had made him wary of filing a lawsuit against McNamee.
"I don't know if I can defend myself," Clemens said. "I think people -- a lot of people have already made their decisions. And that's our country, isn't it? Guilty before innocence -- that's the way our country works now. And then everybody's talking about sue, sue, sue. Should I sue? Well, yeah, let me exhaust -- let me, let me just spend," he said, gesturing as if he were peeling off bills.
"Let me keep spending. But I'm going to explore what I can do, and then I want to see if it's going to be worth it, worth all the headache."
McNamee's lawyers remain undecided whether to sue Clemens for defamation.
"He didn't come right out and call Brian a liar," Ward said. "We're waiting to hear what he says tomorrow. We hope there will be more probing questions asked tomorrow, and we're also waiting to hear what he says before Congress -- if he goes before Congress. I would be surprised if he does."
Eighth on the career list with 354 wins, the 45-year-old Clemens said he was angered McNamee's accusations have been accepted as truth by some.
"It's hogwash for people to even assume this," Clemens said. "Twenty-four, 25 years, Mike. You'd think I'd get an inch of respect. An inch."
Clemens said the descriptions McNamee gave Mitchell of injections "never happened." McNamee said Clemens asked him to inject him in the buttocks because Clemens did not like belly-button shots he presumably could inject himself.
"If I have these needles and these steroids and all these drugs, where did I get 'em?" he said. "Where is the person out there (who) gave 'em to me? Please, please come forward."
McNamee said he obtained the drugs from Radomski or Clemens supplied them.
"Why didn't I keep doing it if it was so good for me? Why didn't I break down? Why didn't my tendons turn to dust?" Clemens said.
Shortly before Mitchell's findings were released Dec. 13, Clemens said McNamee e-mailed him asking where Clemens bought fishing equipment in Cabo San Lucas, Mexico, but never brought up the upcoming report.
McNamee told Mitchell he injected Pettitte with HGH in 2002. Pettitte issued a statement saying he took two HGH injections while rehabbing his elbow.
"I had no knowledge of what Andy was doing," Clemens said. Asked why McNamee would tell the truth about Pettitte and lie about Clemens, Clemens said Pettitte's case was "totally separate."
"I was shocked to learn about Andy's situation," Clemens said. "Had no idea about it."
Clemens wouldn't say what penalty should be assessed on an individual found to have used performance-enhancing drugs.
"I think it's a self-inflicted penalty. They break down quick. It's a quick fix," he said. "They're in and out of the game."
Clemens also discussed his use of Vioxx, an arthritis medication withdrawn from the market in 2004 because a clinical trial revealed increased risk of heart attack and stroke.
"I was eating Vioxx like it was Skittles," Clemens said. "And now -- now these people who are supposedly regulating it, tell me it's bad for my heart."
Clemens has said he was retired after each of the past four seasons but came back each time, spending three seasons with his hometown Houston Astros and then returning to the Yankees last year. He said "you'll never see me pitch again," but hedged slightly and said "probably."
"The higher you get up on the flagpole, the more your butt shows. I understand all that," he said. "But I'm tired of answering to 'em. That's probably why I will not ever play again. I don't want to answer to it. I want to slide off and be just a citizen."
ABC13.com will stream the Roger Clemens press conference live at 4pm Monday.