James Harrison said in an affidavit sent to the NFL by the NFL Players Association that he has never violated the league's policy on performance-enhancing drugs, nor has he met the man who alleged to Al Jazeera that he supplied Harrison with an illegal substance.

The 38-year-old Steelers linebacker is one of four active players the NFL plans to interview as part of an investigation into PED allegations. The affidavit was included with a letter from NFLPA associate general counsel Heather McPhee to NFL senior vice president of labor policy Adolpho Birch. The union included the affidavit to support the position that there is no need for the NFL to interview Harrison in person because the league lacks evidence.

Harrison has said previously that NFL commissioner Roger Goodell will have to come to his house to interview him, adding that the league must show "credible evidence that warrants an interview."

"As a professional athlete, I have met thousands of people during my career," Harrison wrote in the affidavit, "but to the best of my knowledge and recollection, I have never met with the individual who is apparently named Charles Sly ..."

Harrison added: "I have never ingested the substance or product called 'Delta-2'" and "I have never violated the NFL Policy Performance Enhancing Substances."

Charlie Sly is the source for the Al Jazeera report that implicated Harrison and three other active players -- Packers linebackers Clay Matthews and Julius Peppers, and free agent Mike Neal -- as well as recently retired Peyton Manning. Sly since recanted his account, and because of that, the NFLPA argues that the players shouldn't have to discuss the matter with the league.

In her letter, McPhee explained to Birch why Harrison should not be obligated to meet in person with the NFL.

"As you know, neither the CBA or the Policy state that a player must agree to an in-person interview based upon random, baseless verbal remarks or face discipline for failure to cooperate with a league investigation. The NFLPA and Mr. Harrison have simply asked the NFL to meet its obligation as a reasonable, sophisticated employer to perform rigorous due diligence prior to demanding interview with employees."

Last month, NFL spokesman Brian McCarthy said that the league plans to interview Manning.

"The NFLPA and NFL are obligated and have a shared responsibility to look into allegations that could impact the integrity of competition on the field and the health of our players," McCarthy said, via NFL.com. "We have been obtaining and reviewing numerous records, conducting multiple interviews and working with other entities. We have made no conclusions but the report merits a review, including interviews with the players named."

Manning repeatedly denied the PED allegations earlier this year, calling the report "garbage," adding, "I can guarantee you [an] investigation will find a big, fat nothing."