HOUSTON — A federal judge says he's agonizing over the status of a defamation lawsuit Roger Clemens filed against his former personal trainer, who accused the pitcher of using performance-enhancing drugs.

U.S. District Judge Keith P. Ellison said during a court hearing Monday that he's studying whether the lawsuit should be thrown out. A dismissal would come on the grounds that Brian McNamee's claims against Clemens were protected because he made them as a part of his cooperation with federal authorities investigating the player.

Clemens sued McNamee in January after his former trainer told baseball investigator George Mitchell that the seven-time Cy Young Award winner used steroids and human growth hormone.