The NFL Players Association has signed off on the protocol for an HGH population study that will allow blood to be drawn from players to facilitate the study before the start of the regular season pending league approval a source told FOX Sports on Monday.

The NFLPA and the NFL were close to an agreement shortly before the start of training camp but had to iron out issues with the study which is designed to establish the normal average level of HGH in a player's body. The union and the league jointly appointed a team of physicians to conduct the study but had yet to reach a full agreement.

As far as the NFLPA is concerned the agreement on the protocol is in place. The union wanted the blood that will be drawn to be designated as testable only for the population study and not to be retested down the line once an agreement on testing and punishment for positive tests is in place. The agreement the NFLPA has signed and sent to the league states the blood they will allow to be withdrawn in the coming weeks will only be tested for the population study the source said.

An NFL spokesman declined to comment when asked if the league has signed off or will soon sign off on the agreement for the protocol of the population study.

Last month when reports of an agreement on the overall study surfaced league spokesman Greg Aiello said in a statement “We are in active discussions with the NFLPA regarding the implementation of HGH testing for NFL players. Those discussions are focused on a full resolution of any remaining issues including the role of a population study.”

The study is viewed by some as a step toward full-blown testing though the league has been adamant it’s not necessary.