Meanwhile, the cycling world is eagerly -- and in some cases, perhaps, anxiously -- awaiting to hear what Armstrong has to say.

As the World Anti-Doping Agency noted, Armstrong could begin to redeem himself by speaking out about others in cycling with deep involvement in doping.

That's what former cyclist John Eustice expects when Armstrong speaks.

"I think what he'll do is explain how it all works," he said.

Willerton agreed, saying it's one last way for Armstrong to control the narrative swirling around him.

"He's cornered in the sense that he wants to maintain control and he knows that he holds the keys to the people around him who were complicit in what he did," Willerton said. "And that's really the most valuable thing he has to offer at this point."

However, on Tuesday, a source familiar with the matter denied to CNN a report in The New York Times that Armstrong was planning to testify against several powerful people in cycling who have facilitated doping.

The admissions could also have legal ramifications for Armstrong.

SCA Promotions paid Armstrong millions for his Tour de France wins, and now wants its money back. Armstrong sued the company after it raised questions about allegations involving him, and testified under oath that he'd never doped, attorney Jeff Tillotson said Wednesday.

"No matter what he says tomorrow night, based on the evidence we have, we have a compelling legal case for the return of the money we paid him," he said. "But we're specifically looking to see which of the doping allegations that we raised and developed in our case he's going to acknowledge as true."

Meanwhile, the federal government is evaluating whether it will intervene in a whistle-blower lawsuit filed by a former Armstrong teammate. The lawsuit accuses managers for the team they both raced for of defrauding the federal government of millions of dollars because they knew about the drug use and didn't do anything.

A source familiar with the matter confirmed to CNN that lawyers for Armstrong are in discussions with the Justice Department regarding the case. The government has until Thursday to intervene, not intervene or ask for an extension, the source said.

The Justice Department declined Tuesday to comment on potential civil action against Armstrong, saying the whistle-blower suit is under court seal.

A spokesman for the U.S. Postal Service told CNN it could not discuss any of the legal issues associated with Armstrong and their prior relationship.