The NFL and players union are talking again about starting to test for human growth hormone as early as the upcoming season.
The labor agreement that ended the NFL lockout in 2011 allowed the league to test players for HGH - once the union approved the process. The NFL Players Association says it favors testing, but has reservations about the appeals process.
Supplemental HGH is a banned substance that is hard to detect and used by athletes for what are believed to be a variety of benefits, whether real or only perceived - such as increasing speed and improving vision.
Among the health problems connected to HGH are diabetes, cardiac dysfunction and arthritis.
NFL spokesman Greg Aiello says the discussions are focused "on a full resolution of any remaining issues."