After joining the NFL as a seventh-round pick of the Jets in 1997, Ferguson played 159 career games with the Jets, Cowboys and Dolphins. He played for Bill Parcells at every stop.
"Jason was a key contributor on three different teams for many years at one of the NFL's toughest jobs," Parcells said in a team-released statement. "I am grateful and I will miss him."
Ferguson had said he considered retiring earlier in the offseason but was buoyed by the fact the Dolphins wanted him back.
There was no immediate explanation given for his sudden retirement, although it could be a combination of his recovery from last year's injury and the prospect of having to stay in shape for eight weeks while sitting out his suspension.
"You get what you put into this game. I would like to thank my family, the fans and the organizations that I have been a part of for their continued support throughout my career, it's been an absolute blessing to play this long," Ferguson said in a statement. "I have built a lot of relationships, you develop an extended family playing this game; I would like to thank that extended family, the teammates, the coaches, the support staffs that have all played a part of a great ride."
NO PICK IN SUPPLEMENTAL DRAFT: The Dolphins were not active in today's supplemental draft, which saw running back Harvey Unga and Illinois defensive tackle Josh Price-Brent taken in the seventh round by Chicago and Dallas, respectively.