NEW YORK -- Hours after the players' union voted Friday to accept an NFL proposal on drug policy changes that included HGH testing, the league says it is not a done deal.

Josh Gordon's suspension has been reduced to 10 games following the NFLPA's approval of the league's new drug testing policy, per sources. AP Photo/Tony Dejak

Player representatives to the union voted Friday to implement testing for human growth hormone for the 2014 NFL season. HGH testing was originally agreed upon in 2011, but the players have balked at the science in the testing and the appeals process for positive tests.

They also approved a league proposal to significantly increase the threshold for positive marijuana tests. Some players have complained that the NFL threshold of 15 nanograms per milliliter is so low that anyone within the vicinity of people smoking marijuana could test positive. The threshold has been increased to 35 ng/ml.

But league spokesman Greg Aiello told ESPN Senior NFL Analyst Chris Mortensen that "there continue to be significant unresolved issues" with the drug policy. With no agreement in place Saturday afternoon, suspended Broncos wide receiver Wes Welker and Cowboys cornerback Orlando Scandrick -- who would be eligible to return to their teams once an agreement is finalized, a league source told ESPN NFL Insider Adam Schefter -- were not able to be added to their teams' rosters for Week 2.

Welker -- whose suspension would be lifted with the new agreement -- was not on the Broncos' active roster, according to the Denver Post.

The NFLPA released a statement earlier Saturday that said: "We hope to have final agreements, including effective date for players with adjusted discipline, very soon.''

Overall changes are retroactive for players suspended under previous policies, as well as for those in the appeal process.

Browns wide receiver Josh Gordon's yearlong suspension has been reduced to 10 games, a source told Schefter.

Welker was suspended for amphetamine use in the offseason, but punishment for that is being switched from the performance enhancers policy to the substance abuse program -- except for in-season violations.

A two-game suspension will be issued for a player convicted of driving under the influence. But an NFL proposal to immediately suspend a player, owner, coach, team executive or league employee for a DUI arrest was rejected by the union.

Both sides agreed to arbitration for appeals under the substance abuse and the PED policies. The NFL and NFL Players Association will hire between three and five arbitrators.

They also will retain independent investigators to review cases in which player confidentiality under the drug policy has been breached. Punishment for leaks could range up to $500,000 and/or termination of a job.

"This is an historic moment for our players and our league," NFLPA President Eric Winston said. "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."

Information from The Associated Press was used in this report.