BALTIMORE -- Orioles first baseman Rafael Palmeiro was suspended Monday for 10 days by Major League Baseball for violating its Joint Drug Prevention and Treatment Program and began serving the suspension immediately.

Palmeiro, 40, is the highest-profile player to test positive under the current policy adopted earlier this year. He reached the 3,000-hit plateau on July 15, becoming the fourth player in history to accumulate 3,000 hits and 500 home runs. He has 569 career homers and has been considered a strong candidate for induction into baseball's Hall of Fame after he retires.

He became the fourth player in Major League history to amass 3,000 hits and 500 home runs, joining Hank Aaron, Eddie Murray and Willie Mays.

On March 17, Palmeiro vehemently denied in front of a House Subcommittee in Washington, D.C., that he used any performance-enhancing drugs. Palmeiro, along with teammate Sammy Sosa, Mark McGwire and Jose Canseco, were called to testify after Canseco wrote in his book: "Juiced: Wild Times, Rampant 'Roids, Smash Hits, and How Baseball Got Big" that he injected Palmeiro and McGwire with steroids while he was their teammate.

Palmeiro learned of the oncoming suspension recently and appealed it through the Players Association, but the Major League Baseball Arbitration Panel denied his appeal.

"I told the truth, and today I am telling the truth again that I did not do this intentionally or knowingly," he said in a conference call. "I hope the fans understand that I worked very hard over a long 20-year career. I put in a lot of time and a lot of effort in my career. I made a mistake and I am facing it. I hope people learn from my mistake and I hope the fans forgive me.

"I went in front of Congress and I was honest with Congress. There's no absolute reason for me to do anything at this stage of my career. There's nothing for me to gain and everything for me to lose. I knew I was approaching 3,000 hits. I was not about to put everything on the line, my reputation and everything that I've worked for so hard in my life to do anything like this. It just makes no sense."

Palmeiro and the Orioles released a statement before the conference call.

Rafael Palmeiro's Suspension

"At the outset, let me say that under the rules of the basic agreement and the order of the independent arbitrator, there is an order of confidentiality governing the specifics of this case," Palmeiro wrote. "I will attempt to state as much as I can and be as forthright as possible, but there will be issues I can't address based on orders imposed on me by the basic agreement and the arbitration process. I am here to make it very clear that I have never intentionally used steroids. Never. Ever. Period.

"When I found out that I failed a test under the new drug policy, I filed a grievance and challenged the suspension on the basis that I have never intentionally taken a banned substance. Ultimately, although I never intentionally put a banned substance into my body -- the independent arbitrator ruled that I had to be suspended under the terms of the program."

Palmeiro said he does not have an explanation for the positive test.

"I am sure you will ask how I tested positive for a banned substance. As I look back, I don't have a specific answer to give. Unfortunately, I wasn't able to explain to the arbitrator how the banned substance entered my body. The arbitrator did not find that I used a banned substance intentionally -- in fact, he said he found my testimony to be compelling -- but he ruled that I could not meet the heavy burden imposed on players who test positive under the new drug policy."

Palmeiro said he will accept his suspension.

"I want to apologize to MLB, the Baltimore Orioles organization, my teammates, and most of all, my fans. Given my role with the No Tolerance Committee and my relationships with Congress, I feel the need to communicate a serious message to my fellow players and to kids everywhere. All of us have to be responsible and exercise extreme care in what we put in our body. I hope that all MLB players and kids will learn from what has happened to me. I have never intentionally used a banned substance, but I unfortunately wasn't careful enough."

Orioles owner Peter Angelos offered his support to Palmeiro in a statement.

"I am truly saddened by today's events," Angelos said. "I have known Rafael Palmeiro for many years. He is a fine person, a great player and a true asset to his community. I know from personal experience that his accomplishments are due to hard work and his dedication to the game.

"I know that Rafael will accept the penalty under Baseball's important Drug Policy and that he will return to be a productive member of the Orioles."

Vice president Mike Flanagan also issued a statement, saying the club will miss Palmeiro.

"I am obviously disappointed to hear the news of this suspension," Flanagan said. "Raffy has been a friend of mine for many years. He is one of the most dedicated and hard-working players in baseball. I know he would not violate the rules intentionally. I look forward to his return. We will surely miss him and his contribution to the club."

Palmeiro said players and kids need to know the risks of being unaware of what substances they take.

"You just have to be careful with what you take," he said. "You have to make sure you see a doctor. You have to make sure you are taking supplements from a reputable source and be very careful with what you take. It happened to me and it can happen to anyone."

Palmeiro said he put in a call to Sen. Tom Davis (R-Va.) and will attempt to reach Congressman Henry Waxman (D-Ca.), who were both members of the Subcommittee and were working with Palmeiro on a no-tolerance drug program in baseball.

Because of the confidentiality agreement with MLB, Palmeiro could not reveal when he tested positive or filed the appeal.

"I can't talk about when I learned about it but I can talk about that, yes, it is an embarrassing situation," he said. "It's very unfortunate this had to happen to me, especially this year thinking it was going to be my last year and knowing I was going to get to 3,000 hits."

Meanwhile, Palmeiro's legacy is now in question. He said he realizes his numbers are now under scrutiny and there could potentially be a cloud over his career and his chances for the Hall of Fame.

"That's really not for me to determine," he said. "I hope that people look at my whole career and appreciate that I've given everything that I've got. I respect the game. I respect my opponents. I respect the players that came before me. I respect the Hall of Fame. If they think I'm worthy enough, I would be very honored. If they don't I gave it all that I had for this game."