Prosecutors trying to prove Barry Bonds lied when he denied knowingly using performance-enhancing drugs suffered a setback yesterday, with a federal judge in San Francisco saying she might toss some of the strongest evidence against the home-run king.

U.S. District Judge Susan Illston said her "preliminary thoughts" were to exclude from trial three 2000-2001 positive drug tests that prosecutors say belong to Bonds unless there is a direct link that the urine samples came from the former San Francisco Giants slugger.

"If there's no testimony to establish that, I don't think any of them work," Illston said.

The only person who can do that seems to be Bonds' personal trainer, Greg Anderson, who spent more than a year behind bars for refusing to speak to a federal grand jury investigating Bonds. And Anderson's attorney, Mark Geragos, has said his client will not testify against Bonds at the trial, scheduled to start March 2.

Without someone to authenticate that the test results were from Bonds' urine, Illston said claims that the tests were Bonds' were "classic hearsay."

Based on the same logic, Illston said she likely also would exclude a doping calendar and other papers seized by federal investigators at Anderson's home.

She was inclined, however, to allow a recorded conversation between Anderson and Bonds' former personal assistant Steve Hoskins in which they discuss injecting steroids. Hoskins recorded the conversation without Anderson's knowledge.

Illston will issue a formal decision on the evidence discussed yesterday at a later date. She also will hold a separate hearing on whether to allow testimony from expert doctors the government hopes would persuade a jury that changes in Bonds' body were due to steroid use.

PITCHER SHEETS MAY NEED ELBOW SURGERY

Free agent right-hander Ben Sheets could be headed for elbow surgery after contract negotiations with the Texas Rangers fell through because of the injury.

Texas had been discussing a two-year deal with Sheets, the NL starter in the All-Star game last season, a person familiar with the talks said yesterday, speaking on condition of anonymity because the deal never was finalized.

A physical revealed that the torn flexor tendon Sheets sustained last season apparently has not healed, the person said.

Sheets went 13-9 with a 3.09 ERA in 31 starts and made $12.1 million last season.

ELSEWHERE

Blue Jays: Left-hander Brian Tallet and Toronto agreed yesterday to a one-year contract worth $1,015,000 and avoided salary arbitration. Tallet went 1-2 with a 2.88 ERA in a career-high 51 games last season.

Twins: Reliever Matt Guerrier and Minnesota agreed yesterday on a one-year contract worth $1,475,000, avoiding salary arbitration. The 30-year-old right-hander was 6-9 with a 5.19 ERA last season.

Padres: Cliff Floyd agreed to a $750,000, one-year deal with San Diego yesterday. Floyd goes from playing in the World Series with Tampa Bay to a team that lost 99 games and finished last in the NL West.