Mitchell, Commissioner Bud Selig and Don Fehr, the executive director of the Players Association, all are invited and have agreed to appear before the committee next month.

"We look forward to their testimony on whether the Mitchell report's recommendations will be adopted and whether additional measures are needed," the Committee chairman Henry Waxman and ranking minority member Tom Davis said in a joint statement. "We want to commend Commissioner Selig for authorizing this investigation and thank Senator Mitchell for his dedication to this effort."

Mitchell's report offers 19 recommendations to beef up the current drug policy in three areas: investigation, education and improved drug testing. Only six of them -- all in the area of drug testing -- must be collectively bargained with the union.

Selig said on Thursday that he "embraced" those recommendations and intends to implement as many of them as he can immediately.

A spokesman for the committee said Mitchell had accepted the Tuesday invitation and that Fehr had said he would cooperate if there was a hearing. But according to Major League Baseball, Selig had a conflict in his schedule, having already agreed to accept an award in Cleveland on Tuesday night.

Davis and Waxman oversee the committee that hosted the now infamous St. Patrick's Day hearing in 2005, in which players Mark McGwire, Sammy Sosa, Rafael Palmiero, Curt Schilling, Jose Canseco and Frank Thomas were subpoenaed to appear, along with a number of MLB executives, including Selig.

The day-long hearing led to MLB and the union re-opening the sport's drug policy for the second time, primarily to stiffen the penalties for players using performance enhancing drugs.

Congressional pressure was one of the primary motivations for Selig to commission Mitchell and his committee, charging them with investigating baseball's steroid era, the result of which was his 311-page report.