Five National Basketball Association (search) players invited to testify about steroids have yet to agree to appear before a House committee that has concerns about the league's drug-testing policy, a panel spokesman said.

Dave Marin also said the panel's chairman, Rep. Tom Davis, ranking Democrat Rep. Henry Waxman and Sen. John McCain will introduce a bill this week governing steroid testing in U.S. sports.

NBA commissioner David Stern and players' union director Billy Hunter have agreed to appear Thursday at the panel's third hearing on steroids, after Major League Baseball (search) in March and the National Football League (search) last month.

"The chairman at this point is a little bit disappointed that we don't have a player confirmed for Thursday," said Marin, spokesman for Davis, a Virginia Republican.

"It seems to me that they have more bark than bite. It seems to me that they are better at talking the talk than walking the walk," he added.

"All of the players that were invited are players who have made public statements about the lack of steroid use in basketball and about the need to share that message with kids. ... It's our hope that the players' association will be more aggressive in locating a player or two who can make it on Thursday."

NBA Players Association spokesman Dan Wasserman declined comment.

Marin wouldn't say who the five invited players are, other than to describe them as current players whose teams are not alive in the playoffs.

The committee asked the NBA and other leagues to turn over documents about their steroid-testing programs. On Monday, Davis and Waxman sent NFL commissioner Paul Tagliabue (search) a letter requesting additional information about tests for testosterone and epitestosterone dating to Jan. 1, 1995.

A review of the NBA's documents turned up what Marin called "Shaquille O'Neal-sized holes" in the league's drug policy. He cited the rule that veterans are tested once a year during the preseason.

"One could argue that if there's a group of NBA players more likely to use steroids, it's the veterans who are more prone to injury," Marin said.

He wouldn't discuss in detail the legislation drafted by Davis, Waxman, D-Calif., and McCain, R-Ariz., saying only: "It has more teeth than other legislation that's out there."

The chairman of the House Commerce trade and consumer protection subcommittee, Florida Republican Cliff Stearns, proposed the Drug Free Sports Act (search) on April 26.

His panel, which is conducting its own steroids inquiry, will hold hearings Wednesday and Thursday, with Tagliabue, Stern, Major League Baseball commissioner Bud Selig (search) among the witnesses scheduled to appear.

Selig said Monday he would support federal legislation calling for two-year bans for first-time steroid offenses unless the Major League Baseball Players Association agrees to toughen the sport's drug policy.