The NFL has found "no credible evidence" that the Steelers' James Harrison and the Packers' Clay Matthews and Julius Peppers used prohibited substances, following an investigation into allegations made in a documentary by Al-Jazeera.
The three players were interviewed last week, at their team facilities.
The investigation, which started in January, was led by the NFL's security and legal teams and involved witness interviews, a review of records, research and lab analysis and review,
After the interviews last week, a source close to the situation told ESPN that the players were not confronted with any new evidence or allegations.
Free-agent defensive end Mike Neal is the other player the league plans to interview in connection with its investigation into last winter's Al-Jazeera report. The league interviewed retired quarterback Peyton Manning, who also was named in the report, earlier this offseason and issued a statement last month clearing his name.
Major League Baseball players Ryan Howard and Ryan Zimmerman, who also were named in the report, were also publicly cleared by MLB in August after it concluded its investigation.