The NFL players who reportedly had steroid prescriptions filled by a South Carolina physician have been given a penalty normally reserved for players who test positive for the performance-enhancing drugs, Commissioner Paul Tagliabue said.

The league has concluded an investigation into television and newspaper reports about the prescriptions written by physician James Shortt, and as a result, the players, most of them current or former members of the Carolina Panthers, will be subject to as many as 24 random steroid tests annually, Tagliabue said.

"Every player who was part of the investigation who's still in the league is being tested up to 24 times a year, which is the most important element of putting an end to this," Tagliabue said. "That's why we have not had repeat offenders. That's as important or more important than the discipline. It's testing people up to 24 times a year on a random basis."

None of the players linked to Shortt ever failed a league-sponsored steroid test, leading Tagliabue to tell members of the Senate Commerce Committee during a hearing Wednesday on Capitol Hill that the players had found a way to successfully evade the testing program.

In March, "60 Minutes Wednesday" reported that Shortt filled testosterone prescriptions for Panthers players Jeff Mitchell, Todd Steussie and Todd Sauerbrun. Sauerbrun, a punter now with the Denver Broncos, also obtained syringes and the injectable steroid stanozolol, the report said. Steussie now is with the Tampa Bay Buccaneers. Other former Panthers players linked to Shortt in subsequent reports include tight end Wesley Walls, offensive lineman Kevin Donnalley and defensive end John Milem.

Shortt told HBO in a report aired in August that he treated as many as two dozen NFL players, and provided many of them with steroids or human growth hormone to aid in healing. Shortt has been indicted on federal charges, including 29 counts of distributing steroids and human growth hormone.

Lawmakers have called the NFL's steroid-testing program the best in professional sports, but some drug-testing experts have said the Shortt case demonstrated some of its flaws. The NFL has banned human growth hormone but there is no reliable urine test to detect it, and experts say players could use testosterone but keep it under the threshold for what constitutes a positive test. The league and the players' union agreed this year to lower that threshold.

Tagliabue and NFL Players Association chief Gene Upshaw said in interviews after Wednesday's hearing that they believe placing the players involved at an elevated level of the steroid-testing program will serve as a strong deterrent.

"I have no way of knowing," Tagliabue said when he was asked whether he thought other players league-wide were evading the program in a similar fashion. "I know we have a very good program. If anyone is dumb enough to subject themselves to 24 tests a year, they're stupid."

Tagliabue and Upshaw said the league's investigation of the Shortt case is finished.

"There's no fear that there's a wider problem," Upshaw said. "The report has been completed. We will be, at some point, giving it to Congress. We're satisfied with the results of it. The players that were named publicly are in random for-cause testing. . . . They're in a level in which they're tested 24 times [per year]. . . . What this proves is that you'll eventually get anyone that uses. If you use, we'll find you. You will be found out and then you will suffer the consequences of the program. That's the way it works."

According to an NFL source, the league's report concludes that fewer than 10 players over a four-year span used banned substances obtained from Shortt.

None of the players linked to Shortt has been suspended or fined. Under the NFL's steroid policy, a player is subject to a four-game suspension without pay the first time he tests positive for a banned performance-enhancing substance. The policy also contains a "reasonable-cause testing" provision allowing a player who hasn't tested positive to be subject to an increased number of tests -- like a player who has tested positive -- if he has "documented prior involvement with a prohibited substance" or "exhibits behavioral, physical or psychological symptoms consistent with use of prohibited substances." A positive test prior to entering the league or a violation of the law connected to a prohibited substance also could put a player into this category. Upshaw said the league's report on the Shortt case made it clear that the players belonged in reasonable-cause testing.

Under the steroid policy, each NFL player is tested during the preseason. Seven players per team are selected randomly for testing each week during the season, and each player may be tested six times during the offseason (up from twice, in a change enacted this year).

Tagliabue and Upshaw declined to name the players who have been moved to the elevated stage of the steroid-testing program because of their dealings with Shortt, or even to say exactly how many players are involved. Tagliabue said he believed it's "fewer than 10" players. An NFL source said he believed that Mitchell, Steussie and Sauerbrun were the only active players affected. The league's investigation concluded that the Panthers had no involvement in their players' interactions with Shortt, Tagliabue said.

"There was no involvement of the Panthers," Tagliabue said. "It was basically the abuse of testosterone or other things that showed the limitations of testing. It was not a failure of the program. It was the intrinsic limitations of testing that enabled them to go under the radar."

NFL Commissioner Paul Tagliabue testified at a Senate Commerce Committee hearing on Wednesday.