Federal prosecutors began calling rebuttal witnesses after a former security director for the New York Yankees testified for the defense that he felt key prosecution witness Brian McNamee has "zero" credibility.
Gerald Laveroni, who said he saw McNamee on a daily basis in 2000-2001, was the last of 23 defense witnesses to testify on behalf of Clemens, who is charged with lying to Congress when he testified in 2008 he had never used performance-enhancing drugs.
McNamee testified last month that he had personally injected Clemens with steroids and human growth hormone repeatedly.
Clemens has hotly denied McNamee's allegation, though he did not do so in court. USA Today said Clemens told U.S. District Judge Reggie Walton outside the presence of the jury Monday he would not be taking the stand.
The newspaper said the rebuttal phase of the nine-week trial could be completed quickly enough that the case could go to the jury as early as Tuesday.