WASHINGTON - Congress wants to be prepared when Roger Clemens and his former trainer, Brian McNamee, head to Capitol Hill.

The House hearing involving Clemens, McNamee and Andy Pettitte was postponed Wednesday from Jan. 16 until Feb. 13, giving lawmakers more time to gather evidence and to coordinate their investigation with the Justice Department.

The House Committee on Oversight and Government Reform was to begin meeting with lawyers for the witnesses today.

Plans are still in place for the Jan. 15 hearing before the same committee about the Mitchell Report on baseball's Steroids Era. The witnesses that day will be commissioner Bud Selig, union leader Donald Fehr and former Senate majority leader George Mitchell, the report's author.

Questioned by federal prosecutors last year, McNamee said he injected Clemens with steroids and human growth hormone in 1998, 2000 and 2001. Prosecutors had him repeat those charges to Mitchell, and since the report was issued last month, Clemens has repeatedly and vehemently denied the allegations.

A lawyer for McNamee said Wednesday his client wants immunity from the House committee. McNamee likely will meet today with federal prosecutors.

At the end of last week, Congress asked seven-time Cy Young Award winner Clemens, teammate and friend Pettitte and their ex-trainer, McNamee, to testify under oath. Also invited were former Yankees player Chuck Knoblauch and Kirk Radomski, the former New York Mets clubhouse attendant who was one of the main sources of evidence for the Mitchell Report.

Radomski pleaded guilty in April to federal felony charges of distributing steroids and laundering money, and he is scheduled to be sentenced Feb. 8.

'The Justice Department told the committee it would be helpful if we waited until after Radomski is sentenced,' the committee's minority staff director, David Marin, wrote in an e-mail to The Associated Press. 'This also gives us more time to delve into more recent developments, gather more information, and depose all witnesses before they testify in public.'

Plenty has happened since the committee arranged the Clemens-Pettitte-McNamee hearing.

Clemens, who ranks eighth in major league history with 354 career wins, filed a defamation lawsuit Sunday against McNamee. Also Sunday, a TV interview with Clemens aired in which he said McNamee injected him only with vitamin B-12 and the painkiller lidocaine. The pitcher also held a news conference Monday, when he said, 'I'm going to Congress, and I'm going to tell the truth,' and played a recording of a 17-minute telephone conversation he had with McNamee.

That tape could be among the items requested by the committee, the same House panel that brought sluggers Mark McGwire, Sammy Sosa and Rafael Palmeiro to Capitol Hill in March 2005.

Two attorneys for McNamee urged the committee to obtain a recording of a conversation between his client and investigators who work for Clemens' law firm. That meeting took place Dec. 12, a day before the Mitchell Report was released.