"Despite repeated efforts by Barry Bonds's lawyers to bar the testimony of several current and former major league players in Bonds's perjury trial this month, those athletes will be allowed to take the stand, a federal judge ruled on Monday in San Francisco.

Bonds's defense team had asked Judge Susan Illston of United States District Court to reconsider her previous ruling to let the players testify about their connection to Greg Anderson, Bonds's former trainer, at the trial, which begins March 21.

Those lawyers said the jury was likely to apply "guilt by association" to Bonds when other athletes talk about their dealings with Anderson, who prosecutors say dealt performance-enhancing drugs to those ballplayers — and to Bonds.

But Illston ruled — yet again — in the government's favor, which becomes important because Anderson has refused to testify at the trial. Bonds is facing charges of knowingly lying to a federal grand jury in 2003 about his suspected use of steroids and other drugs that helped his performance.

In a ruling filed Monday, Illston wrote that the athlete witnesses would provide evidence that "is relevant to the question of guilt or innocence in this case." Prosecutors say those witnesses will testify that Anderson gave them performance-enhancing drugs, told them how to use those drugs and explained the efficacy of those substances. At the trial, the prosecutors plan to argue that Bonds, like Anderson's other clients, was "not unwittingly duped into taking steroids."

Allen Ruby, Bonds's lead lawyer, said that he had "no reaction" to the ruling. Prosecutors did not return a phone call for comment. "