Julius Peppers, Clay Matthews and 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 ESPN.

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.

The NFL wrote that it has attempted since early April to schedule interviews with the players, saying delays by the NFL Players Association have "obstructed our ability to conduct and conclude the investigation." The league said it first notified the players about the investigation in January.