Washington (CNN) -- Baseball legend Roger Clemens is accused of throwing a wild pitch as he tries to subpoena certain evidence to fight federal charges that he lied to Congress.
Clemens was among those implicated in a probe by Major League Baseball investigating the illicit use of performance-enhancing drugs. That probe was led by former U.S. Senator George Mitchell.
The seven-time Cy Young award winner has denied using steroids, both during a 2008 congressional hearing on the findings of the Mitchell report, and later in reaction to a six-count indictment last August.
His testimony to Congress was at odds with that of his former trainer, Brian McNamee, and with the Mitchell report, which found a basis to conclude Clemens had used banned substances at points in his career.
Pitcher Andy Pettite, who was a teammate of Clemens on both the New York Yankees and Houston Astros, told league investigators Clemens admitted using human growth hormone.
A few weeks after Clemens testified on Capitol Hill, the congressional committee's leaders asked the Justice Department to launch a perjury probe of Clemens.
That led to his being charged with one count of obstruction of justice, three counts of making false statements and two counts of perjury. The trial is scheduled to start July 6.
Mitchell's law firm, DLA Piper, said in papers filed Friday the judge should reject portions of a Clemens subpoena demanding notes that reflect internal discussions among attorneys who anticipated litigation.
The firm considers such notes "virtually immune" from a subpoena, and cites case law as a basis for the judge to rule against disclosure.
Attorneys for Clemens had also subpoenaed congressional staff for their inside notes and other documents that could help defend against the charges.
But in a filing similar to that of the Mitchell law firm, the counsel for the House committee that investigated baseball said Friday Congress is protected from being compelled to disclose the material Clemens has demanded.
U.S. District Judge Reggie Walton, during previous hearings as the case moved along, said he expected the targets of the subpoenas to fight back. Clemens' defense now has until April 6 to press its case for disclosure of the materials cited in the subpoenas.
The next hearing in the case is set for April 21.
Clemens, nicknamed "the Rocket" during his 24-year career, left baseball in 2007 after playing for the Boston Red Sox, Toronto Blue Jays, Houston Astros and New York Yankees.