Washington, DC  - The NFL Players Association has unanimously approved the league's proposal for a revised drug policy that will now include testing for human growth hormone while raising the threshold on marijuana infractions.

Additionally, the new agreement will move positive tests for amphetamine use from the classification of a performance-enhancing substance to one of abuse, meaning players who currently serving suspensions for amphetamines will likely have those overturned immediately and be eligible to play as soon as this weekend.

Among those players falling into that category are Denver Broncos slot receiver Wes Welker, Dallas Cowboys cornerback Orlando Scandrick and Miami Dolphins defenders Dion Jordan and Reshad Jones.

Cleveland Browns wide receiver Josh Gordon is also expected to have his year- long ban for repeated violations of the substance-abuse policy reduced. Under the new rules, Gordon will now have to sit out only 10 games as a fourth-time offender.

"This is an historic moment for our players and our league," said NFLPA president Eric Winston. "We have collectively bargained drug policies that will keep the game clean and safe, but also provide our players with an unprecedented level of fairness and transparency. Players should be proud of their union for standing up for what was best for the game."

The biggest change to the policy is the addition of hGh testing, which will begin at some point during the 2014 season and represents a significant gain by the NFL in its effort to control the use of performance-enhancing drugs.

In turn, the league agreed to raise the threshold for a positive marijuana test from 15 nanograms per milliliter to 35 while consenting to additional steps for players before they are suspended.

For driving under the influence offenses, players will now be subject to a two-game suspension if convicted or if a plea agreement is entered. The NFL cannot impose any discipline on a player upon his arrest under the new policy, however.

"We stood up and fought for what was right," said NFLPA executive director DeMaurice Smith. "Twenty-five years ago it was NFL players that set out to make the game clean by asking for and collectively bargaining the first drug testing policy in professional sports. Today, this union and these player leaders have approved a policy that will serve the game well for generations of players to come."