NFL, NFLPA at odds over 'credible evidence' in Al-Jazeera report

The NFL is continuing to pursue an investigation of players named in an Al-Jazeera report on performance-enhancing drugs and remains at odds with its players' association over its right to do so.

NFL executive Adolpho Birch sent a letter to the NFLPA on Thursday -- in response to letters the NFLPA sent Tuesday -- asserting the league's right to investigate its players based on the Al-Jazeera report. Birch disputed the union's claim that the NFL must meet a standard of "credible evidence" before players James Harrison, Clay Matthews, Julius Peppers and Mike Neal submit to interviews with league investigators.

"The NFLPA's position ... is fundamentally at odds with the CBA, the Policy on Performance-Enhancing Substances and basic tenets of labor law," Birch, the NFL's senior vice president for labor policy, wrote in Thursday's letter, a copy of which was obtained by ESPN.

"As explained in my June 3 letter, the report that prompted this investigation depicted what appeared to be a network of businesses and persons describing an intricate scheme to provide athletes in several sports with performance-enhancing and other substances. There can be no rational question that a nationally aired documentary report with potential impact on public confidence in the game of football is a sufficient basis upon which to investigate the totality of those claims, including those pertaining to the NFL players."

One of the union's stronger arguments against allowing the investigation is the fact that pharmacist Charlie Sly -- the source for the Al-Jazeera report that implicated the four aforementioned players, retired quarterback Peyton Manning and athletes from other sports -- has since recanted his remarks. Birch disputes the relevance of that argument.

"The fact that statements aired in the report may have been since 'recanted,' while potentially relevant to any ultimate conclusions reached, does not extinguish our need to investigate," Birch wrote. " And it is hardly remarkable or dispositive that an individual would publicly disavow statements for which he may be subject to criminal or civil sanctions."

Birch's Thursday letter asserts that NFL players have the obligation to cooperate with league investigations and could face discipline for failing to do so -- a point sure to be contested by the other side as this dispute progresses.

Notably, none of the letters the union sent earlier this week were on behalf of Manning, who is a former player and could decide to cooperate with the league investigation even as the union defends its current players from having to do so. The NFLPA has been in contact with Manning, whose cooperation could conceivably put the other four players in a difficult position from a public relations standpoint. Some people familiar with his thinking believe he will cooperate.

This dispute came to a head earlier this week when Harrison, who has a history of public arguments with the league over discipline matters, said commissioner Roger Goodell would have to go to his house if he wanted to interview him.