"Effective today, Josh Gordon has been returned to the Reserve/Commissioner Suspended list indefinitely for violating the terms of his conditional reinstatement under the Policy and Program for Substances of Abuse," the league said in a statement.
Gordon, 27, had been suspended by the NFL for most of the previous four seasons because of multiple drug violations. Based on the discipline schedule in the collective bargaining agreement, Gordon would be facing banishment from the league for any positive test, though he could still apply for reinstatement.
Earlier Thursday, Gordon tweeted that he was stepping away from football to focus on his mental health.
"I take my mental health very seriously at this point to ensure I remain able to perform at the highest level. I have recently felt like I could have a better grasp on things mentally. With that said, I will be stepping away from the football field for a bit to focus on my mental health," Gordon said in his statement.
Gordon went on to thank coach Bill Belichick, team owner Robert Kraft, the Patriots organization and the fans. A short time later, the Patriots said in a statement that they support Gordon "in his continued efforts to focus on his health."
Stephen A. : You 'simply can't trust' Gordon
Stephen A. Smith reacts to Josh Gordon being indefinitely suspended by the NFL to focus on his mental health.
"I think we all care for him," safety Devin McCourty said. "He was a great teammate. Worked his butt off while he was here. For us as players we wish him the best personally.
"Football comes and goes," said McCourty, a team captain. "We're all going to compete and we're all going to work hard as far as our job playing football. We're used to adversity when it comes to just playing football. Lose a guy to injury. Guy can't play in a game or whatever that is. Life comes before all of that. So we wish him the best and care about that more than wins and losses."
Another captain, 11-year veteran Matthew Slater, echoed that, saying "We all deal with our own issues, whether that's trying to raise a family, trying to make a marriage work, trying to raise kids in this world. Every man has his own struggles and we all do, players, media, whoever you are. That's life. It's important for us to have a healthy understanding of that and try to appreciate it and have perspective on that, that life is so much bigger than football. Certainly that's the case here and we want to be conscious of that as we support Josh."
Gordon missed the start of Cleveland Browns training camp this season to seek counseling for mental health and anxiety issues. He rejoined the team three weeks later and played in one game for Cleveland before the Browns decided to move on, trading him to New England for a 2019 fifth-round pick.
Gordon participated fully in the team's Wednesday practice.
During Sunday's loss to the Pittsburgh Steelers, Gordon was held to one catch for 19 yards and was targeted just twice. While he played 57 of 62 offensive snaps, he notably wasn't on the field for the team's final fourth-down play. Then, for the first time since he suited up for the Patriots this season, he didn't answer questions from reporters after the game.
Gordon had been elevated to a No. 2 role alongside receiver Julian Edelman, averaging 59 snaps per game over the past nine games. In his absence, the club projects to rely more on Chris Hogan, Cordarrelle Patterson and Phillip Dorsett.
In 11 games with the Patriots, Gordon totaled 40 receptions for 720 yards and three touchdowns.