Several Major League Baseball (search) players and executives are set to appear in front of a House panel today to discuss the problem of steroid use and shine some light on what the MLB's new drug-testing policy does and doesn't do.

"We have a good cross-section of players to tell the story that Major League Baseball is unwilling to tell," Rep. Tom Davis, chairman of the House Government Reform Committee, told FOX News on Wednesday.

Davis said that among the witnesses scheduled to testify are Chicago White Sox slugger Frank Thomas (search) and Boston Red Sox pitcher Curt Schilling (search), both described by Davis as role models in the game who have made the effort to speak out against steroid use.

"Schilling is such an outstanding player and role model. ... He's under no cloud at all as he comes forward," said Davis, a Northern Virginia native who grew up watching the now-defunct Washington Senators.

Even former American League MVP Jose Canseco (search), who wrote a tell-all book describing his own and other players' steroid use, is appearing at the panel hearing to discuss the MLB's January decision to impose a drug-testing policy, Davis said. Canseco was refused immunity before testifying, and his lawyer Robert Saunooke said he will not answer any questions that could incriminate him.

"They told me we can't do the Fifth [Amendment] to every question," Saunooke said. "It's an absolute right of every citizen to not be compelled to give testimony against themselves. They do not make the decision. We do."

Davis told FOX News that his panel is not out to get members of the sport, but he does want players and executives, including commissioner Bud Selig (search), to explain the new policy.

"Baseball has not spoken out against this the way they should have in a proactive role and policed itself and we think it's very important," Davis said.

Also expected to testify is former Oakland and St. Louis star Mark McGwire (search). Saunooke said the appearance by McGwire, who has repeatedly denied using steroids, is part of the reason Canseco sought immunity.

"If he still holds to that lie, then the only way we can disprove that is to give specific instances and talk openly and freely," Saunooke said. "If we can't do that, then our credibility is undermined."

Other witnesses include Sammy Sosa (search) and Rafael Palmeiro (search), both of the Baltimore Orioles. Also testifying are players union head Donald Fehr (search), baseball executive vice presidents Rob Manfred and Sandy Alderson and San Diego general manager Kevin Towers.

New York Yankees slugger Jason Giambi (search), who also was subpoenaed last week, was excused Tuesday from testifying because of his involvement in the ongoing federal investigation into illegal steroid distribution.

Davis said the hearing will focus on the new testing program. On Wednesday, Davis and the committee's ranking Democrat Rep. Henry Waxman (search), D-Calif., wrote Selig and Fehr and raised questions about the policy. Read the letter by clicking here.

The major concerns addressed by the lawmakers deal with weaknesses in the MLB's testing policy in comparison with the Olympic Committee's (search) policy. For instance, they pointed out that Olympics policy calls for a two-year suspension of an athlete for the first offense, whereas a first offense for baseball players is either a 10-day suspension or a fine of $10,000 or less. They added that the players never need to face public identification, and several anabolic steroids, designer drugs and human growth hormone are not prohibited or tested.

"It appears that at least four anabolic steroids recognized by the World Anti-Doping Agency (search) and prohibited for Olympic athletes are still permitted for Major League ballplayers. These include boldione, danazol, quinbolone, and dihydroepiandrostone," the letter reads. "The failure of Major League Baseball to cover designer steroids would appear to be a significant omission."

The letter also states concerns that the new policy requires a four-person supervisory committee to implement key decisions such as off-season testing and prohibition of additional substances, often by unanimous decision. Since the panel includes MLB's executive vice president and the player's union chief operating officer, as well as doctors designated by both sides, management and players are both given veto power, the letter reads.

"The staffing of the Health Policy Advisory Committee raises serious questions about the credibility of the drug-testing policy. ... The policy also permits any single member of the committee to deem that a player's objection to a positive result has a 'reasonable basis,' triggering automatic arbitration," the letter states.

The letter also revealed that "the new policy 'will be suspended immediately' if there is an independent government investigation into drug use in baseball."

"Major League Baseball will say, 'We have [drug-testing] under control.' I think our attorneys who analyze it think maybe it's not quite what it is put out to be," Davis told FOX News.

In an opening statement obtained by The Associated Press, Canseco says that he is not surprised that he and others have ended up in front of a congressional panel.

"I had hoped that what I experienced firsthand, when revealed, would give insight into a darker side of a game that I loved, that maybe it would force baseball to acknowledge it condoned this activity for the sole purpose of increasing revenue at the gate," say the remarks scheduled for delivery Thursday. "Unfortunately, by our presence here today, it is clear that MLB is not interested in admitting the truth."

Davis said he hoped the hearing would shed light on the subject, which in turn could act as "the best disinfectant" for the sullied game.

"What has happened in baseball [and] is happening in other professional sports is athletes, so-called, using steroids. They're basically cheating," Davis said, adding that the pervasive practice is setting a bad example that has led to copycat behavior by a half-million high school students who are now taking steroids.

"This is a dead end," Davis said of steroid use. "It's not only an illegal drug, it can kill you."

The Associated Press contributed to this report.