Prosecutors argue defense lawyer Rusty Hardin has a conflict because he briefly represented Andy Pettitte and Clemens in December 2007, just before the release of a report alleging both players used human growth hormone.
Prosecutors say Hardin shouldn't cross-examine Pettitte when they call him as a witness at a trial scheduled for July. They say that should be handled by another Clemens attorney.
U.S. District Judge Reggie Walton on Tuesday scheduled a hearing on the issue for Feb. 2 and ordered Clemens to attend.
Clemens denies using drugs. But Pettitte admits doing so and says Clemens admitted privately he did as well.
