Griffen played in the first two games of the season, but the situation became unmanageable when he was ruled out prior to Minnesota's Week 3 game against the Bills, NFL Network's Tom Pelissero reported at the time.
The same week, the Vikings sent Griffen and his agent a letter stating that he was not allowed to return to the team facility until he underwent a mental-health evaluation.
"We have been in communication with Everson's medical professionals throughout this process and have relied on his recommendations regarding the appropriate next steps for Everson," Vikings general manager Rick Spielman said in a statement. "We are excited to welcome Everson back to the Vikings and to see him around teammates, coaches, and staff -- people who care deeply about his well-being. Our focus will continue to be on providing an on-going support system for Everson and his family."
In a statement, Griffen said that he is looking forward to rejoining the team he has played for since 2010.
"Being around my teammates and coaches is something I have missed for several weeks," Griffen said "While this is an exciting and positive move forward for me, it is only the next step in a longer process. I look forward to once again putting in the work with the guys and contributing to this team in any way I can. My larger focus remains on addressing my personal health, and I'm hopeful the time will come when I feel comfortable sharing my story and using my platform to bring awareness to these issues. I continue to be extremely grateful for the constant support from my family, my teammates, the Vikings organization and our tremendous fans."