Withdrawal of Armstrong Lieutenants Puts Focus on What They Know In early June, about a week before the United States Anti-Doping Agency informed Lance Armstrong that it was set to file doping charges against him, four members of the 2008 Olympic road cycling team, one by one, sent e-mails to USA Cycling. Each asked that his name be removed from the pool of athletes being considered for this summer's Olympic team. "It's unusual," Steve Johnson, chief executive of USA Cycling, said Sunday. To have four athletes opt out, that's never happened, to my knowledge. The real answer is, I don't, and we don't, know why. Johnson said that he and Jim Miller, USA Cycling's vice president for athletics, never questioned why the riders, George Hincapie, Levi Leipheimer, Christian Vande Velde and David Zabriskie - four of the United States" most accomplished road cyclists - decided they should not be in the mix for the London Olympics. Johnson said other athletes, including Armstrong, had backed out of the Games in the past. He said he assumed they did so because they were too busy with their pro careers. Johnson would not comment on the timing of the decision, which has led some to believe that the four cyclists could be witnesses in the doping case against Armstrong, who could be stripped of his seven Tour de France titles if the antidoping agency punishes him. The four riders have more in common than just the 2008 Olympics: they also were teammates with Armstrong on the United States Postal Service team when he was at the peak of his career. Hincapie, a three-time national road race champion, is the only rider to help Armstrong win all seven of his Tour titles. He has competed in five Olympics and told The Associated Press earlier this year that he would "love to go to a sixth Olympics." Vande Velde, who was fourth in the Tour de France in 2008, was on the Postal Service squad from 1998 to 2003. Earlier this year, he told www.cyclingnews.com, "I want to go to the Olympics really bad." Leipheimer, who won the bronze medal in the individual time trial at the 2008 Beijing Games, rode with Armstrong on the Postal Service in 2000-1, then joined him again in 2009 and 2010 on other teams. Zabriskie, the seven-time national time trial champion, was Armstrong's teammate from 2001 to 2004. USA Cycling announced its Olympic road team on Friday, picking Taylor Phinney, Tejay van Garderen, Chris Horner, Timmy Duggan and Tyler Farrar. "I have no idea what the deal is going on there with those guys," Horner, 40, said of the riders who withdrew. Horner is a former teammate of Armstrong and Leipheimer, but said he had not spoken with either of them about the investigation. "Everybody wants to guess this or that, but I don't think it changed any decision of whether I made the team or not," Horner said. "When I read about it, I said, "That's interesting news." I wonder what's going to follow it. None of the four riders who withdrew, either directly or through team representatives, returned phone calls, responded to e-mails or were available for comment on Sunday. The years the four were Armstrong's teammates are among the years the antidoping agency claims Armstrong and five team officials - the team manager Johan Bruyneel, three doctors and a trainer - were at the heart of a conspiracy in which Armstrong not only used performance-enhancing drugs but also encouraged their use and administered them to other riders. Armstrong needs to file a written submission to the antidoping agency by June 22 before a review board decides if he and the others will be formally charged. But his lawyers are already resisting because, they said, the agency has not given them much information - including the names of the 10 riders the agency has said will testify against Armstrong. Armstrong's lawyers are demanding to know those names. Hincapie, Leipheimer, Vande Velde and Zabriskie are said to have described to the antidoping agency their involvement in the suspected doping scheme, which itself could bring a two-year ban if their doping fell within the limits of the World Anti-Doping Code's eight-year statute of limitations. Yet it is doubtful that they would receive such a ban. The antidoping rules include a provision for athletes who give substantial assistance to authorities in a doping investigation, saying those athletes could receive up to a 75 percent reduction of a punishment. Armstrong is facing a much harsher penalty because the antidoping agency has said it has eyewitness testimony that proves he doped less than eight years ago. Armstrong also could lose the Tour titles he won more than eight years ago, the antidoping agency said, because he has waived his right to a time limit "through false statements, fraudulent concealment or other wrongful conduct."