The 2004 MLB season is full of tremendous expectations. A laundry list of superstars changed teams. Vlad Guerrero and Bartolo Colon to the Angels, Miguel Tejada and Javy Lopez to the Orioles, Billy Wagner to the Phillies, Andy Pettitte and Roger Clemens to the Astros, Curt Schilling and Keith Foulke to the Red Sox, Kevin Brown and Gary Sheffield — and, of course A-Rod — to the Yankees.

Even before Schilling faces down A-Rod at Fenway for the first time, we can be sure 2004 will be memorable for other reasons: We are finally going to find out who’s on steroids.

In January, all of a sudden, it was right there in the State of the Union. The President of the United States called Major League Baseball out on its biggest scandal today. (No, it’s not George Steinbrenner.) The steroids paragraph was in a marquee position too, right after drug testing kids and just before proposals for abstinence and a constitutional amendment limiting marriage to the union of a man and a woman.

For the last few years, steroids have been the dark clouds gathering over Major League Baseball. First, we had Jose Canseco saying that 85 percent of big leaguers were on the juice. OK, Canseco is not the most reliable source. This is the same guy who claims he was black-balled out of baseball.

In 2002, there was the actual confession from 1996 National League MVP Ken Caminiti about his own use of steroids. As to the overall rate of usage, his guess was lower than Canseco’s, but still a whopping 50 percent.

Clearly, this was a problem that could not be ignored. In the 2002 labor agreement that averted a near work stoppage, the Player’s Association agreed to allow testing. The deal called for anonymous testing in 2003 to survey the extent of the problem. A sample of positives greater than 5 percent would mean that real testing with penalties would kick into effect.

The results confirmed that 5-7 percent of major leaguers are using illegal performance enhancers. Not nearly as bad as Canseco and Caminiti claimed, but still a problem. This outcome ensures that if players use in 2004, they will get caught and everyone will finally know. The news might be out sooner.

Following up on President Bush’s speech, the federal government has certainly been making noise. Last September, the offices of the Bay Area Lab Cooperative (BALCO) were raided, as was the home of Barry Bonds’s personal trainer, Greg Anderson. This month, the government indicted BALCO president and CEO Victor Conte Jr. and Anderson on charges of running an illegal drug-distribution operation. Since then, Anderson has admitted that he gave steroids to baseball players, but no names have been released — so far.

Bonds insists that he’s never taken steroids and is willing to be tested every day of the season. It might not be a bad idea. Even before the Anderson scandal, there was speculation that Bonds was on the juice. After all, he weighed 190 pounds in 1997. Now, he’s jacked at 228 and has hit 164 homers over the past three seasons despite the fact that he has aged into his late thirties. 164 dingers in three years? Bonds didn’t get to 164 career round-trippers until his seventh and final year in Pittsburgh in 1992.

In all fairness, things have changed a lot over the last decade in baseball — including the shape of Bonds’s head. Since the strike season of 1994, baseballs have been flying out of the park at an astounding rate for any number of reasons: smaller parks, juiced baseballs, lighter bats, bad pitching and others you can choose from. But Bonds has peaked between ages 37-39. And, oh yeah, there is that head thing.

This is something that needs to be resolved. Baseball is a sport that prides itself on history. In no other sport do records flow so easily off of peoples’ tongues: 755, 56, 61 (not a record anymore, but 73 doesn’t sound right yet). The NFL and NBA don’t have that, and I don’t think it’s just because the numbers are bigger.

Baseball insists on comparing players and teams across generations. Bonds’s last three seasons have elevated him into the highest echelon of all-time greats. An unprecedented three consecutive MVP awards to put his record total at six.

He now has 658 career homers. He’ll pass his godfather Willie Mays’s total of 660 in the season’s first week, and he should surpass Babe Ruth by the spring of 2005. After that, Hank Aaron’s 755 should not be a problem if he plays out his contract and keeps up anything close to his current pace. Oh, next year he’ll break the all-time record for walks, but everyone (not just chicks) digs the long ball.

Bonds is not the only big name under the gun. Gary Sheffield and Jason Giambi have ties to BALCO, although Giambi claims all he did was visit the plant. There have been rumors about Sammy Sosa — not that there is any evidence that Sosa would do something illegal to get an edge, right?

As for Giambi, he has reported to training camp, and all everyone can talk about is how much thinner he looks. Did he stop using? He says the weight loss is marginal and only a product of rehabbing his knee and eating healthier. I believe him, but the questions will always be there.

I doubt anyone is going to be dumb enough to get caught using steroids now. For some reason, testing will disappear if the overall rate of usage drops below 2.5 percent in consecutive years. That seems a little ridiculous, especially when the most damaging rumors seem to focus on only a few elite players. Baseball needs to end all questions about steroids now and permanently.

As it is, it’s already too late. Now, all of the records and accomplishments of players like Bonds and Sosa in recent years will always be questioned.