The strength coach for Roger Clemens would not have had access to or the authority to give the star pitcher injections, according to testimony from a team doctor Thursday in the baseball legend’s perjury trial.

Clemens told Congress in a 2008 deposition that he was routinely injected with vitamin B12 by his strength coach and that four or five syringes of the liquid vitamin were “already lined up ready to go” after baseball games.

But a doctor for one of Clemens’s former teams, the Houston Astros, testified that his ballplayers were never provided with such injections because he considered the vitamin ineffective. He also said he never saw pre-loaded needles in the clubhouse.

The testimony by David Lintner, the Astros’ doctor, began to lay the groundwork for prosecutors who are trying to prove that Clemens obstructed Congress when he described under oath the injections he received from strength coach Brian McNamee.

Clemens is accused of committing perjury, making false statements and obstructing Congress when he denied ever having taken performance-enhancing drugs under questioning by House investigators in depositions and lawmakers at a nationally televised hearing.

Under cross-examination, Lintner agreed that Clemens would not necessarily have known that strength coaches and athletic trainers were not authorized to give injections. During the three seasons he worked with Clemens, Lintner also said he saw no outward signs that the powerhouse pitcher was using steroids.

Federal prosecutors later called a steroid expert from the Drug Enforcement Agency to suggest that Clemens could have avoided detection, but still helped his recovery, by taking a minimal dosage of the banned substances.

Jurors heard briefly from Brian Cashman, general manager of the New York Yankees, who is expected to testify Thursday afternoon about Clemens’s performance on the team and his relationship with McNamee, who was put on the Yankees’ payroll at Clemens’s request.

Cashman, a star baseball player at Georgetown Prep and Catholic University, made one blunder on the witness stand when he testified that he had won five World Series tities as general manager. He quickly amended the number.

“Correction,” he told assistant U.S. Attorney Steven Durham. “It was four.”

After the court broke for lunch, Cashman told reporters “I wish it was five.”

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