Posted by Sabrina B. @gametimegirl

The Barry Bonds legal team will try to deliver a damaging blow to the federal government’s efforts to prosecute Bonds for perjury during a hearing on Friday in a federal court in San Francisco.

The lawyers will ask U.S. District Court Judge Susan Ilston to reject the prosecutors’ attempts to use drug calendars, laboratory ledgers, test results, handwritten drug notes marked “Barry,” and other materials seized in raids during the BALCO investigation. It is an attempt to build upon their victory over federal prosecutors in an appeal last year, a ruling that barred much of the evidence the prosecutors hoped to use against Bonds.

The investigation, which began in 2003, led to charges and guilty pleas from Victor Conte, Balco’s owner; Patrick Arnold, a power lifter and biochemist who developed undetectable steroid compounds for BALCO; and Greg Anderson, Bonds’s personal trainer and a frequent customer of BALCO.

Although the evidence gathered in the investigation offers what prosecutors consider to be powerful proof that Anderson guided Bonds through cycles of steroid use between 2001 and 2003, Anderson’s refusal to testify against Bonds has led to rulings from Ilston and the U.S. Court of Appeals that bar use of much of the evidence in the trial of the perjury charges against Bonds.

The perjury charges are the result of Bonds testimony before a grand jury in 2004 in which he denied use of steroids. Without Anderson’s testimony, the prosecutors are unable to establish a “foundation” for use of the evidence. Only Anderson can confirm the authenticity of the documents.

But in pre-trial court papers filed in the past several weeks, the prosecutors now say they need the documents to introduce the trial jury to their investigation, their findings, and their purpose in calling Bonds before the grand jury. Without an accurate picture of the investigation and BALCO’s pattern of “illegal doping and concealed drug testing,” the trial jury will be unable to comprehend Bonds’s testimony before the grand jury.

Using words such as “context” and “background” and “materiality,” the prosecutors contend that they are entitled to use the BALCO-Anderson evidence as a road map for understanding the nature and the extent of Bond’s false and evasive responses to the prosecutors’ questions before the grand jury.

Frustrated by Anderson’s steadfast refusal to testify (he spent more than a year in jail on a contempt of court charge resulting from his refusal), the prosecutors told Ilston in a brief that Bonds and his lawyers cannot be allowed to use “their good fortune in Anderson’s refusal to testify” as a “magic talisman that precludes any reference to the fact that the agents found documents during the searches.”

The government’s position is that in the grand jury’s investigation of Conte and Anderson, Bonds was a critical witness. Asking Bonds about the drug calendars and the positive drug tests and the other evidence, they say, would help the grand jurors decide whether Conte and Anderson were guilty of illegal drug distribution.

Reminding Ilston that Conte and Anderson were the targets of their investigation when Bonds was summoned to the grand jury, the prosecutors suggest that the false testimony from Bonds obstructed the grand jury’s efforts.

In response to government efforts to use the BALCO-Anderson evidence, the Bonds attorneys say the prosecutors are violating the rulings from Ilston and the higher court that, without testimony from Anderson authenticating the material, it is barred. The government’s argument is, they say, “frivolous” and “specious.”

Accusing the government of “struggling mightily” in its efforts to find a way to use the BALCO documents, the Bonds legal team says that the “reasons for its Herculean labor are transparent: it intends to use the evidence for the purpose proscribed [forbidden]” by the previous rulings.

Although an Ilston ruling for Bonds would hurt the government prosecutors, they still would be able to produce at trial what could be damaging testimony from Kimberly Bell, a former Bonds girlfriend, and Steve Hoskins, a former Bonds personal manager, as well as a reported positive drug test from MLB’s 2003 drug-testing program.

Ilston will listen as both sides present their positions on Friday. Although she may rule on the issues at the close of the hearing, it is more likely that she will issue a ruling later this month. The trial is scheduled to begin on March 21.

Lester Munson, a Chicago lawyer and journalist who reports on investigative and legal issues in the sports industry, is a senior writer for ESPN.com.