By Laird Harrison

SAN FRANCISCO (Reuters) - The perjury case against Barry Bonds is built on testimony from enemies of the home run king who cut deals with the government, defense attorneys said on Thursday in closing arguments at the slugger's trial.

Prosecutors earlier painted Bonds as a slippery superstar who lied to hide his use of performance-enhancing drugs while he closed in on the game's all-time home run record.

Bonds faces up to a decade in prison on each charge in the case, one of the last strands of a national probe into the use of performance-enhancing drugs in professional sports.

He is expected to receive a much lighter sentence if convicted, but the jury which now begins deliberations also will be passing judgment on his professional reputation.

Defense attorneys said tainted witnesses ranged from Bonds' former girlfriend, who discussed changes in the baseball star's anatomy, to a childhood friend turned business associate who taped conversations about Bonds, attorneys said.

Witnesses benefited from working with the government, Bonds attorney Cristina Arguedas said as the former slugger's three-week trial wound to a close.

"They have the power to end careers and ruin lives," she said.

Defense attorneys also tried to undermine the basis of an obstruction of justice charge, saying Bonds could not be held guilty for intentionally obstructing a grand jury because he did not know what the jury was doing.

Bonds, who has pleaded not guilty to the charges of obstruction of justice and lying to a grand jury, took notes as he watched his lawyers.

The charges stem from his testimony to a 2003 grand jury investigating the Bay Area Laboratory Co-operative, or BALCO, in a nationwide probe of use of performance-enhancing drugs in sports.


"All he had to do was tell the truth," Assistant U.S. Attorney Jeffrey Nedrow said in his closing arguments before a packed courtroom. "He chose not to tell the truth and that's why he's here."

The government agreed not to hold him accountable for his 2003 grand jury testimony -- unless he lied to the jury.

"Why would the defendant testify falsely after getting immunity?" Nedrow asked. "The reason was a secret and it was a powerful secret and it was that he had been using anabolic steroids and human growth hormones. He had concern that it would taint his accomplishments."

Nedrow said witnesses' testimony, documents, a secret recording, drug bottles and syringes show Bonds lied to protect his reputation.

Testifying to the grand jury, Bonds admitted getting flaxseed oil, vitamins, protein shakes and creams from his trainer, but he said he had no knowledge of human growth hormones or steroids. He said no one had ever injected him other than medical doctors.

Bonds was one of the greatest players of his time. He was the National League's most valuable player seven times and finished his career in 2007 with 762 home runs, more than any other player in the history of Major League Baseball. He also set a single-season home run record with 73.

Three months after breaking Hank Aaron's career homer record in 2007, a grand jury indicted Bonds on charges of perjury and obstruction of justice.

The case in U.S. District Court, Northern District of California is United States of America v. Barry Lamar Bonds, 07-cr-732.

(Editing by Peter Henderson and Peter Cooney)