Oct. 1, 2006 -- Roger Clemens is "The Rocket," a Major League Baseball superstar since 1984. Now, questions are being raised about how he has peformed so well for so long.
The Los Angeles Times reported Sunday that former pitcher Jason Grimsley claimed in a federal affidavit that Clemens was one of several players who used performance-enhancing drugs.
In a statement, Clemens came out swinging, threatening to sue.
"When it's going to take a serious turn for me … is when one of my sponsors pull out. … Then my lawyers will take over from there," he said in a statement.
The Los Angeles Times story also implicated Clemen's teammate, Andy Pettitte.
Pettitte denied the allegations.
"I've never used any drugs to enhance my performance on a baseball field before," he said.
Grimsley Credibility At Issue ... and There May Never Be a Resolution
Grimsley was caught up in the sprawling scandal involving Barry Bonds and other baseball legends.
According to an affidavit, during questioning by an IRS criminal investigator earlier this year Grimsley indicated that Clemens, Pettitte and others used a range of performance enhancing drugs.
The Times reported that former Most Valuable Player Miguel Tejada was one of several Baltimore Orioles accused of using anabolic steroids.
"I don't have no comment. I don't want to say anything," Tejada said.
What is still not clear is how credible Grimsley's claims are.
Clemens said the two never even worked out together and Grimsley has said he never told investigators some of the things attributed to him.
And even if they are true, proving it is all but impossible, so observers say.
"We know a lot of people have done steroids, but how much proof do we have?" said ESPN columnist Tim Kurkjian. "How are we ever going to enforce anything that was done if it was done ten years ago, two years ago, five years ago?"