Julius Peppers, Clay Matthews, James Harrison to be interviewed by NFL, per report

— -- Green Bay Packers linebackers Julius Peppers and Clay Matthews and Pittsburgh Steelers linebacker James Harrison will be interviewed by the NFL after they were named in an Al-Jazeera America report linking them to performance-enhancing drugs, according to a letter obtained by USA Today Sports.

Adolpho Birch, NFL senior vice president of labor policy and league affairs, wrote that the league will meet with the three players at the start of training camp. The Packers open camp July 26, and the Steelers begin training camp July 29.

Free-agent linebacker Mike Neal will meet with the league by July 22, according to the letter.

Now-retired quarterback Peyton Manning was the highest-profile name linked to PEDs in the Al-Jazeera America documentary that aired in December. It alleged that Manning was given a supply of human growth hormone in 2011 from an Indiana-based anti-aging clinic.

Manning was not mentioned in the NFL letter, but a source told USA Today that the investigation is still progressing. Charlie Sly, a man identified as a pharmacist who allegedly spoke to an undercover reporter working for the network, later recanted his story. 

An NFL Players Association spokesman declined comment to USA Today.