Brian McNamee, who told federal investigators that Clemens used performance-enhancing drugs, contends the pitcher defamed him after McNamee spoke to investigators for former Senate Majority Leader George Mitchell. The summons, filed in Queens Supreme Court last week, preserves McNamee's right to sue, Richard Emery, a lawyer for McNamee, said Tuesday.

Clemens filed his own defamation suit against McNamee in January after the trainer said in the Mitchell Report that he regularly injected Clemens with steroids and human growth hormone. Clemens later told a congressional committee under oath he had never taken steroids.

In the federal case in Texas, McNamee's attorneys say the trainer was forced to talk to investigators under threat of prosecution, rendering him immune from any defamation lawsuit. A federal prosecutor backed McNamee's claim, but a judge has yet to rule on his request to toss the case.