One member of the Greek baseball team and a reserve, both American-born, tested positive for banned substances and will be barred from the Olympics, Greek Olympic officials said Monday, a decision that infuriated the Greek manager.

A.J. Brack, a pitcher with an itinerant minor league career, tested positive for the steroid stanozolol. Derek Nicholson, an outfielder in the Detroit Tigers system who would have played in the Olympics only if another player was removed from the roster, tested positive for a diuretic associated with medicine he took for his high blood pressure. Both tests were conducted by Greek officials before the International Olympic Committee overtook the testing process in mid-July.

"That's unfortunate, and it is appropriate that they will not be able to play," said Baltimore Orioles owner Peter Angelos, a Greek American who is helping bankroll the Olympic team. "He only has himself to blame."

In other news, U.S. sprinter Bernard Williams received a public warning for a positive test for marijuana but will not lose his place on the U.S. Olympic team, the U.S. Anti-Doping Agency announced.

Williams, a Baltimore native who will compete in the 200 meters in Athens, tested positive at a June 5 meet in Seville, Spain. His results from that meet will be expunged.

Greek baseball manager Dusty Rhodes -- an American who took over the team after original manager Rob Derksen died of a heart attack in June -- said Nicholson revealed his medication when he filled out a pre-Olympic form, complete with information from his doctor. But officials from both the Hellenic Olympic Committee, the Greeks' organizational body, and the Greek baseball federation said Nicholson did not give the papers to the proper authorities in time to get the substance placed on an approved list for him.

Rhodes said he suspected Brack's positive test resulted from an over-the-counter vitamin. He said Brack, who plays for the New Haven Cutters in the independent Northeast League, had passed drug tests in the United States.

"People need to understand: They didn't intentionally do anything," Rhodes said in a telephone interview. "These two guys have done everything we've asked them to do on the baseball team, and have done everything the Olympic committee asked them to do on the drug test."

Officials of the Hellenic Olympic Committeesaid that was not the case. Yiorgis Gakis, a spokesman for the HOC, said the rules were the same regardless of who was conducting the test.

"If you want to be innocent, the IOC has a typical procedure," Gakis said. "You need to put a demand in to the medical commission of the IOC, and to explain why you obtain [a drug] and why you have permission to use it. If you don't do that, you are not eligible."

Neither Gakis nor Panagiotis Mitsiopoulos, the head of the Greek baseball federation, would address whether Brack's test could have been from a vitamin supplement, as Rhodes suspects.

"If it's banned," Gakis said, "it's banned. It doesn't matter."

Yiannis Papadogiannakis, the head of the HOC, told reporters, "It is sad to be talking about doping."

The situation is particularly embarrassing for the Greek team, which hopes to spread the popularity of the sport in a country that, until this year, had just two baseball fields. The host country is granted a spot in the eight-team baseball tournament, and Angelos bankrolled the Greek team, which is using almost exclusively players from other countries -- mostly Americans -- who have some form of Greek ancestry.

USADA consulted with the world governing body of track and field (IAAF) in determining the penalty for Williams.

Marijuana falls in a small class of drugs for which athletes are subject to a ban of less than a year because they are banned but not considered performance-enhancing.

Another U.S. track and field athlete, triple jumper Tim Rusan, tested positive for marijuana earlier this year and received the same punishment.

Williams, 26, is probably best known for his role on the U.S. gold medal-winning 4x100 relay team, which was roundly criticized for a lengthy display of preening and showboating after its victory at the Sydney Games.

Staff writer Thomas Heath contributed to this report from Washington.