NEW YORK – Baseball is about to get its official box score on the Steroids Era.

The Mitchell Report is due next week, probably Thursday.

It’s the findings of former Senate Majority Leader George Mitchell’s 20-month investigation into performance-enhancing drugs, a modern-day Black Sox scandal that has tarnished many of the game’s greatest stars and records.

Although some are sure to claim it’s one-sided and outdated, it has given players and executives cause for pause.

“Well, it ain’t Merry Christmas or Happy New Year for somebody,” Cincinnati Reds manager Dusty Baker said.

Shining light into the shadows, the 74-year-old Mitchell brought experience from many fields. The former chairman of The Walt Disney Co., he once was offered a spot on the Supreme Court by President Clinton and famously challenged Lt. Col. Oliver North during the Iran-Contra hearings.

But he also is a director with the World Series champion Red Sox, a role players say makes him hopelessly conflicted and an agent of baseball commissioner Bud Selig, who appointed him. Players also claim Mitchell refused to show those accused the evidence against them, denying them a chance to refute the allegations.

For now, Selig claims not to know what’s inside the report. Suffice to say, midway between Boston wrapping up the Fall Classic and the start of spring training, there are plenty of jittery people around the majors.

“Obviously, it can’t be really good,” New York Mets manager Willie Randolph said. “If there’s some really, really big names, I’m sure it’s going to be a real impact in some ways.”

Outfielders Jose Guillen and Jay Gibbons, linked in media reports to receiving human growth hormone, were suspended Thursday for the first 15 days of next season. The penalties are an indication how baseball might treat any players named by Mitchell.

Although some say Barry Bonds’ home run record – and milestone ball – should be marked with an asterisk, Mitchell noted the Hall of Fame vote in which Mark McGwire was picked on just 23.5 percent of ballots, nowhere near the 75 percent needed for induction.

That election in January was considered the first test on how history will view a period when bulked-up stars amassed bulked-up stats.

“If nothing else, the results of the Hall of Fame voting last week, and the reaction to it, offer fresh evidence that this issue will not just fade away,” Mitchell said then. “Whether you think it fair or not, whether you think it justified or not, Major League Baseball has a cloud over its head, and that cloud will not just go away.”

To some, the drumbeat of suspicion is unheard.

“Now when it comes out, more people seem to be numb to it,” former New York Yankees star Don Mattingly said this week. “If it’s not some huge name, they don’t even pay attention anymore.”

Said Milwaukee manager Ned Yost: “I don’t care one way or the other, to be honest with you.”

Hired by Selig in March 2006, Mitchell and his staff spent millions of dollars interviewing people and collecting evidence. Their task: Provide a history of what happened off the diamond during a time when home run marks that had lasted for decades fell as suddenly strong sluggers changed the balance between pitchers and hitters.

Previously undisclosed names could be tied to steroids and HGH, thanks to the cooperation of former New York Mets clubhouse attendant Kirk Radomski. A national investigation led by the Albany, N.Y., district attorney’s office also is believed to have provided evidence to Mitchell.

Active players largely have resisted cooperating – the Yankees’ Jason Giambi is the only one known to have spoken to the inquiry. Although this wasn’t exactly Sing Along with Mitch, retired players have spoken with Mitchell, who did not have subpoena power.

Selig’s decision to launch an official investigation followed the release of “Game of Shadows,” in which San Francisco Chronicle reporters Mark Fainaru-Wada and Lance Williams said Bonds used performance-enhancing drugs for at least five seasons beginning in 1998.

Bonds, who broke Hank Aaron’s career home run record in August, pleaded not guilty Friday to charges he lied to federal investigators about using performance-enhancing drugs.

The home run king was arraigned in U.S. District Court on four counts of perjury and one of obstruction of justice stemming from a Nov. 15 indictment. If convicted, he could spend more than two years in prison.

Bonds, now a free agent who hopes to play in 2008, has denied knowingly using illegal performance enhancers. He nonetheless became the face of steroid allegations while dozens of other major and minor leaguers tested positive.

“I think we’re all eager to get this era behind us and to get steroids out of this game, growth hormone out of the game, get things that change the competitive balance other than hard work and a desire to be the best ballplayer you can be,” Los Angeles Angels manager Mike Scioscia said.

To former World Anti-Doping Agency leader Dick Pound, baseball is an outlaw sport, refusing to agree to WADA’s standards for testing and discipline.

But athletes in U.S. team sports, protected by collective bargaining agreements and American labor laws, have no interest in international standards.

“I think if you look at attendance, if you look at the health of the game right now, that would suggest that fans have digested what information exists and perhaps assumed that the problem has been addressed, at least for the moment,” San Diego Padres chief executive officer Sandy Alderson said.

While cycling has been hurt by doping allegations, Selig repeatedly says this is a golden age for baseball. The sport drew a record average of 32,785 fans to games this year, breaking the previous mark of 31,423 that was set in 1994 – before a 71/2-month players strike caused a steep drop.

The major leagues set a total attendance mark for the fourth straight season, drawing 79.5 million, up 4.5 percent from last year’s 76 million. Performance, thus far, has been what largely has determined players’ reputations, not whether they are clean or not.

“That may unfortunately be the case,” Alderson said.

By hiring Mitchell, Selig gave himself time to see what other information would emerge. Sensitive to what’s written about baseball and himself in newspapers and what is said on the airwaves, Selig acts at a deliberate pace.

Selig has maintained he didn’t realize performance-enhancing drugs were an issue until 1998, when The Associated Press reported McGwire used androstenedione, a testosterone-producing pill that baseball did not ban until 2004.

When players showed up with bigger biceps and hat sizes at spring training in those years, many in baseball suspected something was going on, but no one could prove it. Once the games started, attention turned to the field.

Even now, with the Mitchell report looming, many fans are more focused on what moves their favorite teams are making.

“We’re all kind of desensitized,” Randolph said. “There will be a reaction, but I think that’s really kind of always short-lived and you’ve got to pick up and move on.”

Associated Press baseball writer Mike Fitzpatrick in Nashville, Tenn., contributed to this report.